This document discusses aerodynamics of high-lift devices used on aircraft wings. It describes various types of high-lift devices including flaps, slats, and spoilers. Flaps are installed on the trailing edge of the wing and increase lift by increasing wing camber. Slats are installed on the leading edge and prevent premature stalling. Spoilers are used for roll control and braking upon landing. The document provides details on how each device affects lift and discusses factors that influence their effectiveness such as wing design and airspeed.
This document contains 23 multiple choice questions that test knowledge of principles of flight. Some key topics covered include aerodynamic forces and stability, aircraft performance, propeller parameters, and effects of center of gravity position. Correct answers are provided for each question to assess understanding of fundamental aerodynamics and flight dynamics concepts.
This document provides a description of patent GB780074 (A) for an airplane stabilizer. It describes attaching a weight below the airplane on cables to lower the center of gravity and increase stability. When stability is threatened, such as during tight turns, the lowered weight provides a greater restoring moment to return the airplane to level flight. The weight can be raised for normal flight and lowered during takeoffs, landings, or bad weather to improve stability and prevent crashes due to loss of control.
This document describes a patent for an airplane stabilizer. It proposes lowering a weighted stabilizer below the airplane to displace the center of gravity downward, increasing stability. This creates a larger restoring moment when the plane rolls or tips. The stabilizer is raised during normal flight but lowered during takeoff, landing, or bad weather. It can also sound an alarm if it contacts an obstruction like a hill during landing.
This document describes a patent application for an airplane stabilizer. It proposes lowering a weighted device below the airplane to displace the center of gravity downward, increasing stability. This creates a restoring moment when the plane rolls or tips that rights the plane. The stabilizer can be raised for normal flight and lowered during takeoffs, landings, or bad weather to improve safety by reducing the risk of stalling or capsizing due to loss of stability.
1. The study aimed to determine the required pilot stick force for the N219-B07 aircraft by varying the size of the aileron, nose balance, tabs, and horn balance. Lower stick force allows for easier control surface deflection, which is necessary for pitching and rolling.
2. Hinge moment coefficients were calculated based on equations that consider initial coefficient, angle of attack, control surface deflection, tab deflection, and other factors. Plots of these coefficients showed relationships with nose balance ratio, helping to optimize design.
3. Calculations were performed at different flight conditions to ensure stick force remained below 50 lbs as required. Optimal ratios were found to be 60% aileron chord,
Aeroelasticity involves the interaction between aerodynamic and elastic forces on aircraft structures. Static aeroelasticity studies how these forces influence design, while dynamic aeroelasticity involves additional inertial forces. Common phenomena include flutter, where vibrations increase due to positive feedback, buffeting from transient vibrations, and divergence, a static instability of lifting surfaces. Methods to delay flutter include increasing structural stiffness, adjusting mass distribution, and reducing coupling between degrees of freedom.
National advisory committee for aeronautics naca.BillyQuezada
This investigation tested an NACA 23012 airfoil with various slotted flap configurations in the Langley 7x10 foot wind tunnel. The goal was to determine the effects of flap shape, slot shape, and flap location on aerodynamic characteristics. Maximum lift coefficients and drag polars for favorable takeoff and climb configurations were identified. The best configuration was further tested in the variable density tunnel at a Reynolds number of 8 million. Data from both tunnels also included plain, split, external airfoil, and Fowler flaps for comparison.
The optimum slotted flap configuration produced higher maximum lift than plain, split, or external airfoil flaps based on low drag at moderate lift, high drag at high lift, and
This document discusses transverse stability at large angles of heel for ships. It begins by explaining that while metacentric height is a useful measure of stability for small angles of heel, righting moment must be considered for larger angles. The document then covers righting arms and moments, cross curves of stability, statical stability curves, and the impact of factors like deck immersion and the center of gravity on stability. It also provides an example of the stability behavior of an idealized circular cylindrical body. In summary, it analyzes ship stability at angles beyond initial upright and identifies key metrics for evaluating stability at larger inclinations.
This document contains 23 multiple choice questions that test knowledge of principles of flight. Some key topics covered include aerodynamic forces and stability, aircraft performance, propeller parameters, and effects of center of gravity position. Correct answers are provided for each question to assess understanding of fundamental aerodynamics and flight dynamics concepts.
This document provides a description of patent GB780074 (A) for an airplane stabilizer. It describes attaching a weight below the airplane on cables to lower the center of gravity and increase stability. When stability is threatened, such as during tight turns, the lowered weight provides a greater restoring moment to return the airplane to level flight. The weight can be raised for normal flight and lowered during takeoffs, landings, or bad weather to improve stability and prevent crashes due to loss of control.
This document describes a patent for an airplane stabilizer. It proposes lowering a weighted stabilizer below the airplane to displace the center of gravity downward, increasing stability. This creates a larger restoring moment when the plane rolls or tips. The stabilizer is raised during normal flight but lowered during takeoff, landing, or bad weather. It can also sound an alarm if it contacts an obstruction like a hill during landing.
This document describes a patent application for an airplane stabilizer. It proposes lowering a weighted device below the airplane to displace the center of gravity downward, increasing stability. This creates a restoring moment when the plane rolls or tips that rights the plane. The stabilizer can be raised for normal flight and lowered during takeoffs, landings, or bad weather to improve safety by reducing the risk of stalling or capsizing due to loss of stability.
1. The study aimed to determine the required pilot stick force for the N219-B07 aircraft by varying the size of the aileron, nose balance, tabs, and horn balance. Lower stick force allows for easier control surface deflection, which is necessary for pitching and rolling.
2. Hinge moment coefficients were calculated based on equations that consider initial coefficient, angle of attack, control surface deflection, tab deflection, and other factors. Plots of these coefficients showed relationships with nose balance ratio, helping to optimize design.
3. Calculations were performed at different flight conditions to ensure stick force remained below 50 lbs as required. Optimal ratios were found to be 60% aileron chord,
Aeroelasticity involves the interaction between aerodynamic and elastic forces on aircraft structures. Static aeroelasticity studies how these forces influence design, while dynamic aeroelasticity involves additional inertial forces. Common phenomena include flutter, where vibrations increase due to positive feedback, buffeting from transient vibrations, and divergence, a static instability of lifting surfaces. Methods to delay flutter include increasing structural stiffness, adjusting mass distribution, and reducing coupling between degrees of freedom.
National advisory committee for aeronautics naca.BillyQuezada
This investigation tested an NACA 23012 airfoil with various slotted flap configurations in the Langley 7x10 foot wind tunnel. The goal was to determine the effects of flap shape, slot shape, and flap location on aerodynamic characteristics. Maximum lift coefficients and drag polars for favorable takeoff and climb configurations were identified. The best configuration was further tested in the variable density tunnel at a Reynolds number of 8 million. Data from both tunnels also included plain, split, external airfoil, and Fowler flaps for comparison.
The optimum slotted flap configuration produced higher maximum lift than plain, split, or external airfoil flaps based on low drag at moderate lift, high drag at high lift, and
This document discusses transverse stability at large angles of heel for ships. It begins by explaining that while metacentric height is a useful measure of stability for small angles of heel, righting moment must be considered for larger angles. The document then covers righting arms and moments, cross curves of stability, statical stability curves, and the impact of factors like deck immersion and the center of gravity on stability. It also provides an example of the stability behavior of an idealized circular cylindrical body. In summary, it analyzes ship stability at angles beyond initial upright and identifies key metrics for evaluating stability at larger inclinations.
Prediction tool for preliminary design assessment of the manoeuvring characte...Enrico Della Valentina
This document describes the development of a prediction tool to assess the manoeuvring characteristics of a twin screw displacement yacht in preliminary design. The tool uses numerical simulations in MARIN's SURSIM software to evaluate how variations in rudder area, position, rate of turn, and metacentric height impact yaw checking, course changing, turning ability, and directional stability. Standard manoeuvres like zigzags and turning circles were simulated across a range of design parameters to provide sensitivity analysis and guidance for design improvement. The results of the simulations are presented and discussed.
This document discusses different types of slopes that can be determined from contour lines on a map including gentle slopes with widely spaced contour lines, steep slopes with closely spaced lines, concave slopes with closely spaced lines at the top and widely spaced at the bottom, and convex slopes with widely spaced lines at the top and closely spaced at the bottom. The speed troops can move and whether grazing fire is possible depends on the slope type. Contour lines provide information on slope steepness and terrain features.
This document provides an overview of a drilling engineering course that covers topics such as drilling fluid hydraulics, flow patterns, pressure drops, and optimization of drilling programs. It discusses laminar and turbulent fluid flow, models for calculating pressure drops, friction factors, bit and surface equipment hydraulics. Methods for determining optimum pump rates, nozzle sizes, and hydraulic horsepower are presented. Cuttings transport models like Moore's and Chien's correlations are introduced to estimate minimum flow rates for effective hole cleaning. The goal of the course is to understand drilling fluid properties and optimize drilling programs for maximum penetration rates.
This document provides an overview of shiphandling theory and practices. It covers key topics such as laws of motion, controllable and uncontrollable forces acting on a ship, terminology, ground tackle, mooring, getting underway, single and twin screw characteristics, standard commands between the conning officer and helm, and maneuvering considerations. The document is intended to teach the essential information needed for shiphandling watches and operations.
The document discusses factors that affect aircraft takeoff and landing performance at airfields, including:
- Runway length required for takeoff versus available length based on aircraft weight and design
- Impact of obstacles that must be cleared during takeoff
- Effects of high temperature and altitude on airfield performance due to lower air density
- Impact of wet runways, wind conditions, and maximum certified landing weight on performance.
The document defines many key terms used in naval architecture. It begins by explaining terms related to ship dimensions such as forward perpendicular, after perpendicular, and length between perpendiculars. It then defines terms describing ship structure and geometry, including sheer, camber, rise of floor, and tumblehome. Finally, it outlines terms pertaining to ship motion like heave, pitch, surge, roll, and yaw. The document provides a comprehensive overview of technical terminology in naval architecture.
1) The document discusses the forces acting on a floating ship, including the resultant weight force and buoyancy force.
2) It explains how changes in weight distribution on a ship, such as additions, removals, or shifts of weight, can cause the center of gravity to move.
3) The document provides equations to calculate the new vertical location of the center of gravity (KG) after weight changes by taking weighted averages or moments of the weight distribution.
This document discusses load standards and the effective width method for bridge engineering according to the Indian Roads Congress (IRC). It outlines various loads that must be considered in bridge design like dead load, live load, impact load, and wind load. It also describes the IRC's standard load classifications for bridges and provides equations for calculating impact percentage and effective slab width. The effective width method per the IRC is described for slabs spanning in one or two directions and cantilever slabs.
The document discusses the aerodynamic properties and geometry of aircraft wings. It describes how wings are formed by airfoils and outlines several key airfoil parameters like chord, thickness, camber, and their ratios. It also discusses wing planform characteristics such as span, taper ratio, sweep, and mean aerodynamic chord. Proper selection of wing geometry parameters like aspect ratio, taper, and twist can optimize an aircraft's aerodynamic qualities including drag, stability, and load distribution.
The document provides an overview of drillstring components and equipment used in drilling engineering. It discusses the main components that make up the drillstring, including drill pipes, drill collars, heavy wall drill pipes, and special tools. Drill pipes extend along most of the drillstring length to transmit torque and weight, while drill collars are used to directly apply weight on the bit. Other equipment discussed include stabilizers, which provide localized support points to control inclination, and reamers/hole-openers. The document provides details on material properties and specifications for different drillstring components.
Horizontal curves provide a transition between two straight sections of roadway. They are necessary for gradual changes in direction when a direct turn is not feasible. Design considerations for horizontal curves include radius, design speed, side friction, and superelevation. Superelevation transitions consist of runoff sections at the beginning and end of curves to transition the pavement cross-slope from normal to fully banked, or vice versa, over a specified length to maintain safety and comfort.
The document discusses transition curves in highways. Transition curves are curves that gradually change the horizontal alignment from straight to circular. This is done to introduce centrifugal force, super elevation, extra widening, and aesthetics gradually for driver comfort and safety. There are three main types of transition curves: spiral, cubic parabola, and lemniscate. The length of the transition curve can be calculated based on the rate of change of centrifugal acceleration, rate of introduction of designed super elevation, or empirical formulas based on vehicle speed and radius of the circular curve. The maximum length from these three criteria is used as the final length of the transition curve.
Transition curves are curves of varying radius used between straight and circular sections of roads or rails. They help provide a gradual change in super elevation to prevent overturning of vehicles. Transition curves have properties like matching the rate of super elevation change and meeting the circular curve tangentially. Their length can be determined using arbitrary gradient, time rate of super elevation change, or rate of radial acceleration change formulas. Common types are the spiral clothoid and cubic parabola curves. The clothoid has a length inversely proportional to its changing radius of curvature, helping provide a smooth transition. Transition curves are important for safety and reducing wear on vehicles.
This document discusses equations for calculating the lift and pitch moment coefficients of a complete aircraft based on the contributions of its components. It states that the total aircraft lift is the sum of the wing lift and horizontal tail lift, accounting for downwash effects. An equation is derived relating the aircraft lift coefficient to the angle of attack, tail efficiency, and contributions from the wing and tail. Similarly, an equation is presented for the aircraft pitch moment coefficient accounting for moments produced by the wing, tail, and center of gravity location. These equations allow determining the proper force and moment distributions between the wing and tail.
Airfoil properties, shapes & structural dynamical features are described. Nomenclature or the classification types are presented along with the application.
Common methods for analysis of the structural dynamics on a wing or blade are presented along with the possible applications.
This document discusses methods for estimating aerodynamic properties of aircraft parts and surfaces needed to determine stability and control characteristics. These include estimating lift curve slope, zero-lift angle of attack, pitch moment, and downwash parameter for wings, horizontal tails, and vertical tails through relationships involving airfoil properties, geometry, and flow characteristics. Semi-empirical equations are presented to calculate these properties for straight tapered wings and tails using parameters like aspect ratio, taper ratio, sweep, and position.
Transition curve and Super-elevation
Transition Curve
Objectives of Transition Curve
Properties Of Transition Curve
Types Of Transition Curve
Length Of Transition Curve
Superelevation
Objective of providing superelevation
Advantages of providing superelevation
Superelevation Formula
Numerical
This document discusses orthographic projection and structural geology concepts including:
- Defining planes and lines with strike/dip and trend/plunge parameters
- Calculating apparent dip, true dip, and line of intersection attitudes from known strike and dip measurements
- Determining strike and dip of a plane given two apparent dip measurements
- Finding the apparent dip or line of intersection trend and plunge from known plane attitudes
This document discusses the principles of ship stability and buoyancy. It defines key concepts like center of gravity, center of buoyancy, metacenter, and stability curves. Archimedes' principle states that the buoyant force on an object equals the weight of the fluid it displaces. For a ship, stability depends on the relationship between the center of gravity and metacenter. A positive metacentric height results in a stable ship that will return to its original position if tilted, while a negative height means the ship is unstable. Stability curves plot righting arm versus angle of heel to analyze a ship's behavior at various inclinations.
Strategic design of aircraft wings have evolved over time for maximum fuel efficiency. One of such ideas involves winglet which has been known
to reduce turbulence at the tip of the wings. This study intends to investigate the
differences in drag and lift forces generated at aeroplane wings with and without winglet at cruising speed using FEM. Simulations were performed in the
SST turbulence model of CFD and the results are compared to that of the experimental and theoretical models. The simulation showed that the lift increased
by 26.0% and the drag decreased by 74.6% for the winglet at cruising speed.
VORTEX DYNAMIC INVESTIGATION OF WING SLOTTED GAP OF SAAB JAS GRIPEN C-LIKE FI...IAEME Publication
Canard fighters generally configured with wing canard-deltas and would generate
an airflow phenomenon producing vortex cores and lifts. The lift distribution would
stall at a high angle of attack (AoA). This study investigated the vortex dynamic of
wing canard delta configurations of the Saab JAS Gripen C-like model which create
different wing planform than other fighters. The slotted leading edge of the Gripen
would develop a strong vortex core on the outer wing, on the same direction with the
spin of wing vortex; the outer core would drag the inner vortex core and strengthened.
Consequently, the vortex core streamlined in a leading edge of the wing would begin
to detach, resulting rolled-up vortices in the wing leading edge followed by a solid
laminar stream which tends to curl out. The trailing edge of the wing tended to
laminarize backward. The result would be a negative surface pressure on the leading
edge above the canard and on the wing which causes more negative surface pressures.
An increase in AoA will generate a closer vortex breakdown location to the wing
leading edge. The location was calculated as the ratio of the axial velocity
Prediction tool for preliminary design assessment of the manoeuvring characte...Enrico Della Valentina
This document describes the development of a prediction tool to assess the manoeuvring characteristics of a twin screw displacement yacht in preliminary design. The tool uses numerical simulations in MARIN's SURSIM software to evaluate how variations in rudder area, position, rate of turn, and metacentric height impact yaw checking, course changing, turning ability, and directional stability. Standard manoeuvres like zigzags and turning circles were simulated across a range of design parameters to provide sensitivity analysis and guidance for design improvement. The results of the simulations are presented and discussed.
This document discusses different types of slopes that can be determined from contour lines on a map including gentle slopes with widely spaced contour lines, steep slopes with closely spaced lines, concave slopes with closely spaced lines at the top and widely spaced at the bottom, and convex slopes with widely spaced lines at the top and closely spaced at the bottom. The speed troops can move and whether grazing fire is possible depends on the slope type. Contour lines provide information on slope steepness and terrain features.
This document provides an overview of a drilling engineering course that covers topics such as drilling fluid hydraulics, flow patterns, pressure drops, and optimization of drilling programs. It discusses laminar and turbulent fluid flow, models for calculating pressure drops, friction factors, bit and surface equipment hydraulics. Methods for determining optimum pump rates, nozzle sizes, and hydraulic horsepower are presented. Cuttings transport models like Moore's and Chien's correlations are introduced to estimate minimum flow rates for effective hole cleaning. The goal of the course is to understand drilling fluid properties and optimize drilling programs for maximum penetration rates.
This document provides an overview of shiphandling theory and practices. It covers key topics such as laws of motion, controllable and uncontrollable forces acting on a ship, terminology, ground tackle, mooring, getting underway, single and twin screw characteristics, standard commands between the conning officer and helm, and maneuvering considerations. The document is intended to teach the essential information needed for shiphandling watches and operations.
The document discusses factors that affect aircraft takeoff and landing performance at airfields, including:
- Runway length required for takeoff versus available length based on aircraft weight and design
- Impact of obstacles that must be cleared during takeoff
- Effects of high temperature and altitude on airfield performance due to lower air density
- Impact of wet runways, wind conditions, and maximum certified landing weight on performance.
The document defines many key terms used in naval architecture. It begins by explaining terms related to ship dimensions such as forward perpendicular, after perpendicular, and length between perpendiculars. It then defines terms describing ship structure and geometry, including sheer, camber, rise of floor, and tumblehome. Finally, it outlines terms pertaining to ship motion like heave, pitch, surge, roll, and yaw. The document provides a comprehensive overview of technical terminology in naval architecture.
1) The document discusses the forces acting on a floating ship, including the resultant weight force and buoyancy force.
2) It explains how changes in weight distribution on a ship, such as additions, removals, or shifts of weight, can cause the center of gravity to move.
3) The document provides equations to calculate the new vertical location of the center of gravity (KG) after weight changes by taking weighted averages or moments of the weight distribution.
This document discusses load standards and the effective width method for bridge engineering according to the Indian Roads Congress (IRC). It outlines various loads that must be considered in bridge design like dead load, live load, impact load, and wind load. It also describes the IRC's standard load classifications for bridges and provides equations for calculating impact percentage and effective slab width. The effective width method per the IRC is described for slabs spanning in one or two directions and cantilever slabs.
The document discusses the aerodynamic properties and geometry of aircraft wings. It describes how wings are formed by airfoils and outlines several key airfoil parameters like chord, thickness, camber, and their ratios. It also discusses wing planform characteristics such as span, taper ratio, sweep, and mean aerodynamic chord. Proper selection of wing geometry parameters like aspect ratio, taper, and twist can optimize an aircraft's aerodynamic qualities including drag, stability, and load distribution.
The document provides an overview of drillstring components and equipment used in drilling engineering. It discusses the main components that make up the drillstring, including drill pipes, drill collars, heavy wall drill pipes, and special tools. Drill pipes extend along most of the drillstring length to transmit torque and weight, while drill collars are used to directly apply weight on the bit. Other equipment discussed include stabilizers, which provide localized support points to control inclination, and reamers/hole-openers. The document provides details on material properties and specifications for different drillstring components.
Horizontal curves provide a transition between two straight sections of roadway. They are necessary for gradual changes in direction when a direct turn is not feasible. Design considerations for horizontal curves include radius, design speed, side friction, and superelevation. Superelevation transitions consist of runoff sections at the beginning and end of curves to transition the pavement cross-slope from normal to fully banked, or vice versa, over a specified length to maintain safety and comfort.
The document discusses transition curves in highways. Transition curves are curves that gradually change the horizontal alignment from straight to circular. This is done to introduce centrifugal force, super elevation, extra widening, and aesthetics gradually for driver comfort and safety. There are three main types of transition curves: spiral, cubic parabola, and lemniscate. The length of the transition curve can be calculated based on the rate of change of centrifugal acceleration, rate of introduction of designed super elevation, or empirical formulas based on vehicle speed and radius of the circular curve. The maximum length from these three criteria is used as the final length of the transition curve.
Transition curves are curves of varying radius used between straight and circular sections of roads or rails. They help provide a gradual change in super elevation to prevent overturning of vehicles. Transition curves have properties like matching the rate of super elevation change and meeting the circular curve tangentially. Their length can be determined using arbitrary gradient, time rate of super elevation change, or rate of radial acceleration change formulas. Common types are the spiral clothoid and cubic parabola curves. The clothoid has a length inversely proportional to its changing radius of curvature, helping provide a smooth transition. Transition curves are important for safety and reducing wear on vehicles.
This document discusses equations for calculating the lift and pitch moment coefficients of a complete aircraft based on the contributions of its components. It states that the total aircraft lift is the sum of the wing lift and horizontal tail lift, accounting for downwash effects. An equation is derived relating the aircraft lift coefficient to the angle of attack, tail efficiency, and contributions from the wing and tail. Similarly, an equation is presented for the aircraft pitch moment coefficient accounting for moments produced by the wing, tail, and center of gravity location. These equations allow determining the proper force and moment distributions between the wing and tail.
Airfoil properties, shapes & structural dynamical features are described. Nomenclature or the classification types are presented along with the application.
Common methods for analysis of the structural dynamics on a wing or blade are presented along with the possible applications.
This document discusses methods for estimating aerodynamic properties of aircraft parts and surfaces needed to determine stability and control characteristics. These include estimating lift curve slope, zero-lift angle of attack, pitch moment, and downwash parameter for wings, horizontal tails, and vertical tails through relationships involving airfoil properties, geometry, and flow characteristics. Semi-empirical equations are presented to calculate these properties for straight tapered wings and tails using parameters like aspect ratio, taper ratio, sweep, and position.
Transition curve and Super-elevation
Transition Curve
Objectives of Transition Curve
Properties Of Transition Curve
Types Of Transition Curve
Length Of Transition Curve
Superelevation
Objective of providing superelevation
Advantages of providing superelevation
Superelevation Formula
Numerical
This document discusses orthographic projection and structural geology concepts including:
- Defining planes and lines with strike/dip and trend/plunge parameters
- Calculating apparent dip, true dip, and line of intersection attitudes from known strike and dip measurements
- Determining strike and dip of a plane given two apparent dip measurements
- Finding the apparent dip or line of intersection trend and plunge from known plane attitudes
This document discusses the principles of ship stability and buoyancy. It defines key concepts like center of gravity, center of buoyancy, metacenter, and stability curves. Archimedes' principle states that the buoyant force on an object equals the weight of the fluid it displaces. For a ship, stability depends on the relationship between the center of gravity and metacenter. A positive metacentric height results in a stable ship that will return to its original position if tilted, while a negative height means the ship is unstable. Stability curves plot righting arm versus angle of heel to analyze a ship's behavior at various inclinations.
Strategic design of aircraft wings have evolved over time for maximum fuel efficiency. One of such ideas involves winglet which has been known
to reduce turbulence at the tip of the wings. This study intends to investigate the
differences in drag and lift forces generated at aeroplane wings with and without winglet at cruising speed using FEM. Simulations were performed in the
SST turbulence model of CFD and the results are compared to that of the experimental and theoretical models. The simulation showed that the lift increased
by 26.0% and the drag decreased by 74.6% for the winglet at cruising speed.
VORTEX DYNAMIC INVESTIGATION OF WING SLOTTED GAP OF SAAB JAS GRIPEN C-LIKE FI...IAEME Publication
Canard fighters generally configured with wing canard-deltas and would generate
an airflow phenomenon producing vortex cores and lifts. The lift distribution would
stall at a high angle of attack (AoA). This study investigated the vortex dynamic of
wing canard delta configurations of the Saab JAS Gripen C-like model which create
different wing planform than other fighters. The slotted leading edge of the Gripen
would develop a strong vortex core on the outer wing, on the same direction with the
spin of wing vortex; the outer core would drag the inner vortex core and strengthened.
Consequently, the vortex core streamlined in a leading edge of the wing would begin
to detach, resulting rolled-up vortices in the wing leading edge followed by a solid
laminar stream which tends to curl out. The trailing edge of the wing tended to
laminarize backward. The result would be a negative surface pressure on the leading
edge above the canard and on the wing which causes more negative surface pressures.
An increase in AoA will generate a closer vortex breakdown location to the wing
leading edge. The location was calculated as the ratio of the axial velocity
The International Journal of Engineering and Science (IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The document discusses aerodynamic analysis of the NACA 0012 airfoil using computational fluid dynamics (CFD). CFD simulations were performed in ANSYS Fluent to analyze flow behavior and calculate aerodynamic forces at varying angles of attack from 0 to 20 degrees. The results obtained from the CFD analysis matched theoretical predictions and experimental data. Key parameters like pressure and velocity distributions, lift and drag coefficients, and lift to drag ratios were evaluated to understand airfoil performance.
This document provides information about measuring the lift and drag of an airfoil. It discusses the basic forces on an airfoil, including lift and drag. It describes how pressure distributions over the airfoil surface can be measured using pressure taps, and how the pressure measurements can be used to calculate lift and drag coefficients. The document outlines the objectives, procedures, and expected results for an experiment using a wind tunnel to acquire pressure distributions on a NACA 2415 airfoil at varying angles of attack and air speeds.
The document summarizes the design process for a business jet capable of carrying 6 passengers up to 1500nm. Calculations were done to determine the required wing design based on the jet's weight and performance parameters. A transonic airfoil was selected, and calculations determined the wing should have an aspect ratio of 7 and wingspan of 27.487m. CFD analysis found the lift force was close to calculations but drag force was much higher, likely due to difficulty calculating drag by hand. The rest of the aircraft was designed around the selected wing.
CFD Analysis of Delta Winged Aircraft – A ReviewIRJET Journal
This document reviews computational fluid dynamics (CFD) analysis that has been conducted on delta wing aircraft and airfoils with surface modifications like dimples. Several studies are summarized that used CFD to analyze how dimples affect lift and drag on airfoils at various angles of attack. Dimples function similarly to vortex generators by creating vortices that delay flow separation and reduce pressure drag. Researchers have found that dimples can increase an aircraft's aerodynamic performance characteristics and maneuverability by reducing drag and stall. The document reviews multiple studies that analyzed different dimple shapes and configurations on symmetric and asymmetric airfoil profiles.
A Good Effect of Airfoil Design While Keeping Angle of Attack by 6 Degreepaperpublications3
Abstract: Airfoil is a shape of wing or blade of (a propeller, rotor or turbine) by which a fluid generates an aerodynamic force. The component of this force perpendicular to the direction of its speed is called lift force and the component parallel to its speed is called drag forces. Here we see that if we set the angle of attack by 6 degree in fluid NACA0012 we found the aerodynamic forces with suitable positive result our research is totally based on iterations method and based on the help of cfd software.
The document discusses the effect of horizontal tail aspect ratio on the lateral-directional stability of airplanes. It first provides background on how the horizontal tail produces lift to balance wing pitching moments. It then describes how increasing the tail's aspect ratio can improve both static rolling stability and damping in the rolling convergence mode, but decrease damping in the spiral mode. The results could be used to better design airplane configurations for improved stability. Equations are presented for estimating contributions to directional stability from various components like the wing, fuselage, and vertical tail, as well as factors like side wash.
This document provides details about conceptual design and performance characteristics for a fighter aircraft. It includes mission requirements, configuration, and performance parameters from previous aircraft design projects. Tables show the crew, role, endurance, payload, combat time, fuel weight, and other design points. The document also discusses the V-n diagram, which plots load factor versus airspeed and depicts the aircraft's structural load limits. It provides equations to calculate points on the V-n diagram curves based on factors like stall speed, maneuvering speed, dive speed, and gust loads.
This document summarizes a computational fluid dynamics (CFD) analysis of flow separation control over an airfoil using a co-flow jet technique. The co-flow jet concept injects a high-velocity jet near the leading edge and sucks air near the trailing edge to enhance mixing and allow the flow to remain attached at high angles of attack. CFD simulations found that the co-flow jet airfoil significantly increased maximum lift, increased stall angle by 5 degrees, and expanded the operating range by 38%. While drag was higher for the co-flow jet airfoil, its lift-to-drag ratio was also much larger, indicating improved aerodynamic efficiency overall. The co-flow jet technique was found to effectively delay flow
The document discusses numerical analysis of variable sweep wings for micro air vehicles (MAVs). It presents computational fluid dynamics (CFD) simulations of MAV models with wings swept at 15° and 40° at various angles of attack. The results show that increasing sweep angle decreases parasite drag and improves aerodynamic performance. A sweep angle of 15° provided the best lift-to-drag ratio at low speeds. Swept wings can help MAVs operate efficiently over a range of speeds and angles of attack.
Synthesis of Research Project-FlappingWingKarthik Ch
This document summarizes research on modeling and simulating a flapping wing mechanism based on the flight of pigeons. The researchers created a 3 degree of freedom parallel mechanism to simulate the flapping, bending, twisting, and other wing motions. They analyzed the mechanism's workspace to identify singularities and implemented inverse kinematics control. Testing showed that increasing flapping amplitude and frequency increased lift, but excessive values caused issues. Future work proposed improving the flexibility of the wing model, implementing feedback control, and further optimizing flapping motion parameters like angle of attack variation.
This document discusses airplane performance analysis. It covers static and dynamic performance topics like thrust required, thrust available, maximum velocity, rate of climb, takeoff, landing, equations of motion, drag polar, and drag types. It provides equations and examples to calculate thrust required, lift-to-drag ratio, and velocity for minimum thrust required.
The document summarizes a computational fluid dynamics study of flow over clean and loaded wings using ANSYS Fluent. It describes simulating flow over an airfoil at angles from 0-20 degrees both with and without a missile model attached. The results show that boundary layer separation begins around 15 degrees for the clean wing and occurs at a lower angle for the loaded wing. However, issues with meshing prevented analysis of the loaded wing case. Increasing angle of attack was found to increase lift forces until stall occurred due to vortex shedding beyond 20 degrees.
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For Video Lecture of this presentation: https://youtu.be/NAjezfbWh4Y
The topics covered in this session are, drag, categories of drag, drag polar equation and drag polar graph, drag polar derivation, induced drag coefficient.
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Aerodynamics Characteristics Of Airplanes At High AOASandra Long
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This document discusses the fundamentals of aircraft aerodynamics. It introduces aerodynamics as the science of air motion and forces on aircraft. Aerodynamics is divided into sections based on speed and altitude ranges, including incompressible flows, subsonic, transonic, supersonic, and hypersonic aerodynamics. The main components of an aircraft are also introduced, including the wing, fuselage, tail unit, landing gear, and power plant. Coordinate systems used in aerodynamic analysis are defined.
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5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
1. SECTION 1. AERODYNAMICS OF LIFTING SURFACES
THEME 7. AERODYNAMICS OF THE WING HIGH-LIFT DEVICES
Swept wings of rather small area with an airfoil of rather small camber and
relative thickness are applied in modern aircraft with the purpose of flight speed
increasing. Such wings can not provide large lift on landing modes because of early
flow stall. The problem of increasing lifting properties for modern wings at high angles
of attack for shortening of take-off and landing distance is very actual now. For this
purpose wings are equipped with special design elements which allow to increase the
value of C ya max in the area of critical angles of attack α st . These elements working on
modes of takeoff, landing and maneuver are called wing high-lift devices.
The set of effective high-lift devices applied in aircraft is wide enough (table 7.1).
There distinguish rigid, jet, combination high-lift devices and high-lift devices based on
the boundary layer control (BLC).
The high-lift devices are installed on the leading and trailing wing edges. The
high-lift devices of the wing trailing edge are realized by flaps of various types (Fig.
7.1): simple flap, one-slotted flap, Fowler extension flap, double-slotted flap, plane flap
etc.
Flaps are applied to increase the lift of an airplane at keeping of its position
(keeping the angle of attack). They are extended while taking off and landing. The lift
grows due to increase of wing camber.
Extension flaps consisting of several sections are used on modern airplanes.
Multi-section configuration allows bending the wing smoothly, and air jets streaming on
the upper surfaces of sections through slots, providing smooth continuous flow at high
angles of sections deflection. The theoretical substantiation of multi-slotted flaps was
given by
S. A. Chaplygin. Such flaps additionally increase lift due to the growth of wing area.
81
2. Fig. 7.1. High-lift devices of the wing trailing edge:
a) - flap ΔC yа h − l .dev . = 0 .7 δ flap = 30 o ; b) - one-slotted flap;
c) - one-slotted extended flap ΔC yа h− l .dev . = 1.1 ;
d) - double-slotted flap ΔC yа h − l .dev . = 1.4 ; e) - Fowler flap;
f) - plane flap ΔC yа h− l .dev . = 0 .8 ÷ 0 .9 δ flap = 60 o .
An angle between chords of main flap section in deflected and non-deflected
positions is called flap setting δ flap . It is measured in a plane, perpendicular to axis of
rotation; δ flap > 0 if flap is deflected downwards.
The flap are used not only for improvement of take-off and landing
characteristics, but also for direct control of lift, rational redistribution of loading which
effects a wing, and also for drag reduction.
The high-lift devices of the wing leading edge are usually made as the deflected
slats (Fig. 7.2): movable slat, Krueger slat, deflecting nose etc.
The slats are intended for prevention of premature flow stalling from wing. It is
reached due to wing camber at the leading edge and jet blowing onto the upper wing
surface through a slot.
An angle characterizing turn of coordinate system related with the slat at its
deflection is called slat setting δ slat .
The slat is the wing-shaped and locates along the wing leading edge. At
increasing of angle α under the influence of sucking force the slat is put forward into
operative location.
82
3. Fig. 7.2. High-lift devices of the wing leading edge:
a) - sliding slat; b) - extended slat ΔC yа h − l .dev . = 0 .6 ÷ 0 .9 ;
c) - deflected nose ΔC yа h− l .dev . = 0 .55 ÷ 0 .75 δ з = 60 o .
Choice of high-lift devices in each particular case is determined by such criteria,
as increment of the lift coefficient ΔC yа h− l .dev . provided with it (Fig. 7.3, 7.4) and
inevitable drag increment. The high-lift devices type allowing to receive the required
take-off and landing characteristics of the airplane should be got out right at the
beginning of the designing process.
Fig. 7.3. Influence of deflection of split flap, Fig. 7.4. Influence of slat deflection
flap and slotted wing onto C ya = f ( α ) onto C ya = f ( α )
The major factor causing an increasing of a wing C ya factor at deflection of high-
lift devices is the growing of its cross-sections concavity. The growth of C ya is also
promoted by increase of the wing area at using movable flaps.
83
4. Let's consider the influence of high-lift
devices deflection of the trailing edge onto
structure of flow about the wing. Comparison
of pressure factor C p distributions chordwise
at non-deflected and extended flaps (fig. 7.5)
shows, that the flap deflection causes an
essential growth of rarefaction along total
upper wing surface, and not just on its
deflected part. The appreciable increase of
overpressure is observed along the total lower
surface. As a result the lift coefficient
Fig. 7.5. Pressure factor distribution
increases.
along airfoil outline with flap and
For effective realization of factor C ya
without it
increasing it is necessary to provide attached
flow about wing with the extended high-lift devices. As it's known, this is promoted by
boundary layer control (BLC) by increasing of kinetic energy of decelerated air layer
(blown off) or its removal from the flow (suction) (Fig. 7.6). The change of dependence
of lift coefficient is similar to slat application (Fig. 7.4). The control system of
circulation ΔC yа h − l .dev . = 0 .6 ÷ 0 .8 at C μ = 0 .3 , systems with flow blowing-off from
slot on a wing tail part (Fig. 7.7) and system of blower of wing surface by jets from the
engine (Fig. 7.8) are also examples of jet high-lift devices. The intensity of blower
(blowing-off) is characterized by a factor of momentum:
kg ⋅ m
msV j s s ,
Cμ = (7.1)
q∞ S j N 2
2 ⋅m
m
where m s is the air consumption per second, V j is the jet speed, S j is the wing area
maintained by high-lift devices, q∞ is the dynamic pressure.
84
5. Fig. 7.6. Systems for boundary layer control ΔC yа h − l .dev . = 0 .6 ÷ 0 .8 :
a) - suction through a slot, b) - distributed suction through the porous or
punched surface, c) - blow-off from a slot.
Fig. 7.7. Systems with flow blow-off from a slot on wing tail part:
a) - flap with blowing of the upper surface ΔC yа h− l .dev . = 7 ÷ 8 , C μ ≈ 2 ;
b) - jet flap ΔC yа h− l .dev . = 4 ÷ 5 ; c) - ejector flap ΔC yа h− l .dev . = 6 ÷ 7 , C μ ≈ 2 .
Fig. 7.8. A system of wing surface blowing by engine jets:
à) - blowing of the flap upper surface δ flap = π 3 , C μ ≈ 2 , ΔC yа h− l .dev . ≈ 8 ;
b) flap lower surface δ flap = 40 o 60 o , ΔC yа h− l .dev . = 6 ...7 .
The spoilers are panels installed on the wing which can be deflected outside to
spoil the flow over the wing. They are made as rotary or extended (fig. 7.9) and
installed both on the upper and on the lower wing surfaces. Spoiler either turbulizes or
stalls the flow depending on altitude of its moving out. The pressure redistributes both
on the upper and on the lower surfaces.
85
6. Fig. 7.9. Spoilers: a) - rotary; b) - extended.
Spoilers are used for roll control (instead of ailerons).
Spoilers are also applied for shortening of run at landing and aborted takeoff. In
such case they are mounted on the wing upper surface directly ahead of flaps and
deflected simultaneously on both wings. It causes flow stalling from the wing upper
surface and high-lift devices. As a result, the lift coefficient C yа abruptly decreases and
the drag coefficient C xа grows, loading onto wheels also grows, that allows to increase
braking force considerably. Such spoilers are called ground spoilers. For landing angles
of attack ΔC yа h− l .dev . = −0 .7 ...0 .75 .
Generally, a type and span of high-lift devices, wing plan form, panel flap chord
b flap , flap chord b flap , type of wing airfoil and its relative thickness с , etc. influence
ΔC yа h− l .dev . value.
For swept wings the effectiveness of high-lift devices is abruptly reduced at
angles close to α st . Similar effect is caused by aspect ratio decreasing.
86
7. The table 7.1. High-lift devices.
Increase of Angle of
High-lift devices maximum lift basic airfoil at Remarks
max. lilt
Effects of all high-lift devices
depend on shape of basic airfoil.
- 15 °
Basic airfoil
Increase camber. Much drag when
fully lowered. Nose-down pitching
50 % 12 °
Plain or camber moment.
flap
Increase camber. Even more drag
than plain flap. Nose-down pitching
60 % 14 °
moment.
Split flap
Increase camber and wing area.
Much drag. Nose-down pitching
90 % 13 °
moment.
Zap flap
Control of boundary layer. Increase
camber. Stalling delayed. Not so
65 % 16 °
much drag.
Slotted flap
Same as single-slotted flap only
more so. Treble slots sometimes
70 % 18 °
used.
Double-slotted flap
Increase camber and wing area. Best
flaps for lift. Complicated
90 % 15 °
mechanism. Nose-down pitching
Fowler flap moment.
Same as Fowler flap only more so.
Treble slots sometimes used.
100 % 20 °
Double-slotted
Fowler flap
Nose-flap hinging about leading
edge. Reduces lift at small
50 % 25 °
deflections. Nose-up pitching
Krueger slat moment.
87
8. Table 7.1. High-lift devices.
Increase of Angle of
High-lift devices maximum lift basic airfoil at Remarks
max. lilt
Controls boundary layer. Slight
extra drag at high speeds.
40 % 20 °
Slotted wing
Controls boundary layer. Extra drag
at high speeds. Nose-up pitching
50 % 20 °
moment.
Fixed slat
Controls boundary layer. Increases
camber and area. Greater angles of
60 % 22 °
attack. Nose-up pitching moment.
Movable slat
More control of boundary layer.
Increased camber and area. Pitching
75 % 25 °
moment can be neutralized.
Slat and slotted
fl Complicated mechanisms. The best
combination for lift; treble slots may
120 % 28 °
Slat and double- be used. Pitching moment can be
slotted Fowler flap neutralized.
Effect depends very much on details
of arrangement.
80 % 16 °
Blown flap
Depends even more on angle and
velocity of jet.
60 % ?
Jet flap
Note. Since the effects of these devices depend upon the shape of the basic
airfoil, and the exact design of the devices themselves, the values given can only be
considered as approximations. To simplify the diagram the airfoils and the flaps have
been set at small angles, and not at the angles giving maximum lift.
88
9. THEME 8. WING PROFILE DRAG
The profile drag is the sum of surface- friction drag and drag of pressure caused
by pressure redistribution along the streamlined surface due to viscosity influence
(sometimes latter item is called form drag).
It is necessary to mean that surface-friction drag is the main part of profile drag of
streamlined bodies (therefore it is often considered that C xp ≈ C x fr ). This circumstance
is taken into account in approximate methods of C xp calculation. It is possible to adopt,
that C xp does not depend on angles of attack in modes of attached flow and then
calculation of C xp is performed at α = 0 (small change of C xp on angles of attack is
taken into account at definition of induced drag, having put an effective aspect ratio
λ eff , or separate items at polar calculating). In range of Mach numbers less than 4 ...5
all drag components (wave, induced, profile) can be determined separately from each
other. At that the wave and induced drag are well calculated without the account of
viscosity. However at M∞ ≥ 4 ...5 (zone of hypersonic speeds) there are effects of
viscous interaction, which cause the necessity of the account of viscosity and pressure
mutual influence, that makes wave and profile drag inter-related.
Below we shall consider the method of calculation for streamlined bodies at
M∞ ≤ 4 ...5 (without the account of viscous interaction).
The most widespread engineering method of C xp calculation is method CAGI.
According to this method the profile drag is determined as surface-friction drag of a flat
plate with introduction of correction multipliers which are taking into account an
additional part of drag from pressure forces. According to CAGI method the wing
profile drag is determined by the formula
C xp = 2С f η c η м (8.1)
where С f is the drag coefficient of friction of one side of a flat plate in a flow of
incompressible fluid at identical to wing: Reynolds number Re and position of a point
of laminar boundary layer transition into turbulent x t ; the factor double value takes into
89
10. account flow about the upper and lower surfaces; η м is the multiplier which is taking
into account a compressibility (Mach number M ∞ ); η c is the factor taking into
account contribution of pressure forces into profile drag.
Generally С f , η c and η м are also the function of x t , Re , с , M i.e.
V∞ l
С f = f ( Re, x t ) ; ηc = f (c , x t ) ; η м = f ( M , x t ) . At that Re = , where length
ν∞
of a mean aerodynamic chord bA is used as characteristic length l . It is convenient to
write Reynolds number as a function dependent on Mach number and flight altitude
Re = Vb A ν = M b A f ( H ) , (8.2)
where f ( H ) = a∞ ν∞ , a∞ is the speed of a sound and ν∞ is the kinematic factor of
viscosity are determined under the tables of standard atmosphere depending on flight
altitude. Or
f ( H ) = 2 .33⎛ 1 − H + H
⎜
⎝ 12
2 ⎞ ⋅ 107 , m − 1
⎟
535⎠ [ ] (8.3)
The most complex and insufficiently investigated is the definition of position of
transition point x T . From the standpoint of drag decreasing it is desirable to have the
body (wing) streamlined completely by laminar flow (i.e. x t = 1 ). Only profile C xp and
induced C xi drags exist in subsonic flow. Polar formula is written as
2
C xa = C x 0 + AC ya , where C x0 = C xp . The parameter K max is determined as
1
K max = and at this mode C xa = 2C x 0 = 2C xp , i.e. the profile drag is a half of
2 AC x 0
full drag). However it practically can not be achieved. Any irregularities, rivets, welded
seams etc. are a source of turbulence. As a rule, at a preliminary designing stage the
precise value of x t is not known. Usually one assumes that the body (wing) is
streamlined completely by turbulent flow ( x t = 0 ), that overestimates full drag and
required thrust of the power plant. At actual value ( x t > 0 ) the excess of a thrust
(power) is received which can go onto increasing of maneuverable properties of the
90
11. airplane. Nevertheless, it is necessary to note deep researches, which are being
performed on decreasing of C xp . In case of x т = 0 it is possible to assume the
following computational formulae for C xp definition:
0 ,087 2 1 + 5c 2 M
Cf = ; ηc = 1 + 2c + 9 c ; η м = . (8.4)
( lg Re − 1,6 ) 2 1 + 0 .2 M 2
If the value x t ≠ 0 is known, then it is necessary to address to the diagrams. It is
also possible to use approximate formulae (at x t ≤ 0 .5 ):
0 ,087
Cf = (1 − x t ) + 1,Re
33
xt ;
( lg Re − 1,6 ) 2
ηc = 1 + 2ce − 2 ,4 x t + 9 c 2 e − 4 x t ; (8.5)
⎛ ⎞
⎜
ηм = ⎜
1
⎜ 1 + 0 ,2 M 2
2 ⎟
(
+ 0 ,055 x t M ⎟ 1 + 5 c 2 M .
⎟
)
⎝ ⎠
If there are various sources of turbulence on a streamlined surface (design
superstructures, joints of skin sheets, riveted and welded seams, slot of high-lift devices
of the wing leading edge etc.), then it is necessary to locate the point of transition in a
place of source presence.
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