REVIEW ON CRITICAL SPEED IMPROVEMENT IN SINGLE CYLINDER ENGINE VALVE TRAINijiert bestjournal
The purpose of valve train is to operate the inlet and outlet valves of the engine. The valve train m ainly consists of rocker arm,push rod,cam,poppet valve and spring for kee p the valves closed position. The Greaves G400WG en gine valve train is operated at the maximum speed of 3600 rpm. The main objective of this project is to improve the valve train speed up to safe speed limit that is up to 5000 rpm. The valve spring parameters are optimized based on space availability,stress limit,stiffness,buckl ing of pushrod and natural frequency of the system. The optimized valv e spring configuration is used in the push rod type valve train and the valve train dynamics for different engine speed is studie d using commercially available multi-body dynamic A DMAS software. A comparative valve train dynamics analysis is also c arried out with the existing and optimized valve sp ring combinations. It is observed that valve jump engine speed with respect to optimized valve spring is enhanced to considerab le amount when compared to the existing valve spring configuration. Design improvements include detail study on following topi cs:1. Valve Spring Stiffness. 2. Push rod buckling. 3. Valve closing Velocity. 4. Contact stress between cam and follower
REVIEW ON CRITICAL SPEED IMPROVEMENT IN SINGLE CYLINDER ENGINE VALVE TRAINijiert bestjournal
The purpose of valve train is to operate the inlet and outlet valves of the engine. The valve train m ainly consists of rocker arm,push rod,cam,poppet valve and spring for kee p the valves closed position. The Greaves G400WG en gine valve train is operated at the maximum speed of 3600 rpm. The main objective of this project is to improve the valve train speed up to safe speed limit that is up to 5000 rpm. The valve spring parameters are optimized based on space availability,stress limit,stiffness,buckl ing of pushrod and natural frequency of the system. The optimized valv e spring configuration is used in the push rod type valve train and the valve train dynamics for different engine speed is studie d using commercially available multi-body dynamic A DMAS software. A comparative valve train dynamics analysis is also c arried out with the existing and optimized valve sp ring combinations. It is observed that valve jump engine speed with respect to optimized valve spring is enhanced to considerab le amount when compared to the existing valve spring configuration. Design improvements include detail study on following topi cs:1. Valve Spring Stiffness. 2. Push rod buckling. 3. Valve closing Velocity. 4. Contact stress between cam and follower
Parametric study of a low cost pneumatic system controlled by onoff solenoid ...eSAT Journals
Abstract Expensive proportional valves are dominantly used in pneumatic positioning systems even with low demanding accuracy
positioning tasks, which deprive pneumatic systems from its economical advantages. Thereby, using low cost on/off solenoid
valves instead of proportional valves has been a topic of research in the last decades. In this paper, a parametric study is
conducted to investigate the effect of using low-cost 3/2 internally pilot on/off solenoid valves to control a double acting cylinder
and study the system nonlinear response to on/off and PWM input signal. Matlab ® Simscape library is used to model and
simulate the system. The model is validated though experimental measurements of the system behavior. The model is used to study
and decrease the nonlinear pressure response associated with the cylinder chambers in addition to the evaluation of the dead
zone and operating range of the on/off solenoid valve when operated with PWM signal. The results show that using a meter-in
flow control and having a near constant cylinder back pressure can reduce the nonlinearity. An orifice of 1e-6 m2 can reduce the
pressure variation by 80% but increase the transient time. Connecting an accumulator with 1 liter volume can result in 50%
reduction in rod side pressure variation. The model has been used to predict the PWM parameters as well. It has been found that
the most suitable parameters for this valve are 20 Hz and duty cycle from 12 to 65%. These results encourage going further with
controlling a pneumatic position system using low-cost control valves and a simple controller.
Keywords: Pneumatic Control, PWM, On/Off Valves, Simscape, Matlab
In chemical processing industry the pressure inside the vessel is increase due to many reasons. An
important responsibility of a chemical plant designer is to make sure that a plant under design, can be operated
safely, it is provided with primary, secondary safety arrangement. One of the dangerous situations that can be
arises during operation inability of a system to a pressure higher than that for which it was designed. With
designing pressure safety release valve for inside vessel pressure, should be giving priority to mechanical systems
to release inside pressure. The reasons are many for increase/exceed inside pressure. Most flow applications
require regulating the flow of liquid, and usually the parameter of concern is the pressure. This paper focuses on
the review on design of self regulating pressure valve by using transient finite element analysis. There are many
authors work on this pressure valve. This paper includes study of various papers related to self regulating pressure
valve. In this project focus on exchange of liquid between two chambers, where in it is required that flow be shut
off when a certain pressure is reached .Electronic valves are available, however the intent of this design project is
have a total mechanical system, which has an in built response mechanism.
The need for high pump performance and efficiency continue to encourage the study of flow between two parallel co-rotating discs in multiple discs pump or turbine. Therefore, this study entails the design, construction and CFD simulation of a 3D Tesla pump model axisymmetric swirling flow in order to enhance the understanding of Tesla pump for future development.
Method of solution entails designing and construction of a small prototype tesla pump and then using the design geometry and parameters to design and perform numerical simulation. The results of the numerical simulation were then analyzed.
The result obtained indicates static pressure to have minimum value of -4.7791Pa at the outlet and 13.777Pa at the pump inlet and with velocity magnitude having minimum velocity of 0.00m/s and maximum velocity of 4.12m/s. The strength of the velocity was seen to be very high at the pump outlet. The analysis radial velocity showed minimum value of -0.508m/s and maximum value of 3.981m/s with the radial velocity vector being concentrated at the discs periphery and outlet.
Model simulation results exhibited smooth pressure and velocity profiles. With the 3D simulation all flow variables are able to be predicted.
The need for high pump performance and efficiency continue to encourage the study of flow between two parallel co-rotating discs in multiple discs pump or turbine. Therefore, this study entails the design, construction and CFD simulation of a 3D Tesla pump model axisymmetric swirling flow in order to enhance the understanding of Tesla pump for future development.
Method of solution entails designing and construction of a small prototype tesla pump and then using the design geometry and parameters to design and perform numerical simulation. The results of the numerical simulation were then analyzed.
The result obtained indicates static pressure to have minimum value of -4.7791Pa at the outlet and 13.777Pa at the pump inlet and with velocity magnitude having minimum velocity of 0.00m/s and maximum velocity of 4.12m/s. The strength of the velocity was seen to be very high at the pump outlet. The analysis radial velocity showed minimum value of -0.508m/s and maximum value of 3.981m/s with the radial velocity vector being concentrated at the discs periphery and outlet.
Model simulation results exhibited smooth pressure and velocity profiles. With the 3D simulation all flow variables are able to be predicted.
Design of Industrial Electro-Hydraulic Valves, New ApproachIJERA Editor
A fully flexible valve actuation systems are being under consideration as an enabling technology for advanced internal combustion engine concepts. Electro-hydraulic valve actuator systems are being considered as a dominating variable valve technology. Compared to the servo control system, the system using a proportional valve has the advantages of low price, high anti-pollution ability and high reliability. Unlike existing electromechanical or servo actuated electro-hydraulic valve actuation systems, precise valve motion control is achieved with an internal feedback mechanism. This feedback mechanism can be turned on or off in real-time using simple two state valves which helps reduce the system cost and enables mass production.
Conceptual Designing and Numerical Modeling of Micro Pulse Jet for Controllin...CSCJournals
A conceptual design and numerical model of Micro Pulse Jet has been developed to investigate the flow separation. This valve is designed to generate the stream line vortices to suppress the flow separation by enhancing the mixing of the flows between free stream and separated flow of the boundary layer through pitched jet orifice of very small width. This paper describes not only the conceptual modeling of Micro Pulse Jet but also presenting the numerical analysis and results of steady and unsteady pulse of micro jet. The unsteady pulse of the valve is simulated by the periodic inlet boundary condition through mathematical model. A 2-D ramp with 20 degrees divergence is selected. The divergence of the lower wall of the ramp is large enough to produce a strong adverse pressure gradient causing the boundary layer to separate. A jet orifice is introduced at the upstream of the divergent portion of the ramp and the effect of steady and unsteady jet is analyzed. The main inlet boundary condition is almost of 0.2 Mach. The jet amplitude is characterized by the velocity ratio (Vj/V∞) in between 0 to 5 and the jet pulse frequency is varying between 0 to 100 Hz. A comparison between the steady and unsteady Micro Pulse jet is also done, which indicates the mass flow requirement for pulse micro jet is reduced significantly as compare to the steady jet for the flow separation control.
REVIEW OF FLOW DISTRIBUTION NETWORK ANALYSIS FOR DISCHARGE SIDE OF CENTRIFUGA...ijiert bestjournal
A computational fluid dynamics (CFD) analysis has been conducted to find the pressure losses for dividing and combining fluid flow through a junction of discharge system. Simulations are performed for a range of flow ratios and equations are developed for pressure loss coefficients at junctions. A mathematical model based on s uccessive approximations then would be employed to estimate the pressure losses. The proposed CFD based strategy can be used for the analysis of all the three pipe branches of s ome diameter are selected along with equal length so that only the effect of bend angle can be st udied. The effect of bend angle,pipe diameter,pipe length,reynolds number on the resistan ce coefficient is studied. The software used is CATIA for modeling and ANSYS fluent for analysis purpose.
Butterfly valves are widely used in hydro power plants to regulate and control the flow
through hydraulic turbines. That’s why it is important to design the valve in such a way that it can give
best performance so that optimum efficiency can be achieved in hydraulic power plants. Conventionally
that the models of large size valves are straight in the laboratory to determine their performance
characteristics. This is a time consuming and costly process. High computing facility along with the use
of numerical techniques can give the solution to any fluid flow problem in a lesser time. In this research
work flow analysis through butterfly valve with aspect ratio 1/3 has been performed using
computational software. For modelling the valve ICEM CFD 12 has been used. Valve characteristics
such as flow coefficient and head loss coefficient has been determined using CFX 12 for different valve
opening angle as 30°,60°,75°, and 90° (taking 90°as full opening of the valve) for incompressible fluid.
Value of head loss coefficient obtained from numerical analysis has been compared with the
experimental results.
Study on a linear relationship between limited pressure difference and coil c...ISA Interchange
On/off solenoid valves with PWM control are widely used in all types of vehicle electro-hydraulic control systems respecting to their desirable properties of reliable, low cost and fast acting. However, it can hardly achieve a linear hydraulic modulation by using on/off valves mainly due to the nonlinear behaviors of valve dynamics and fluid, which affects the control accuracy significantly. In this paper, a linear relationship between limited pressure difference and coil current of an on/off valve in its critical closed state is proposed and illustrated, which has a great potential to be applied to improve hydraulic control performance. The hydraulic braking system of case study is modeled. The linear correspondence between limited pressure difference and coil current of the inlet valve is simulated and further verified experimentally. Based on validated simulation models, the impacts of key parameters are researched. The limited pressure difference affected by environmental temperatures is experimentally studied, and the amended linear relation is given according to the test data.
Optimization of Modified Sliding Mode Controller for an Electro-hydraulic Act...IJECEIAES
This paper presents the design of the modified sliding mode controller (MSMC) for the purpose of tracking the nonlinear system with mismatched disturbance. Provided that the performance of the designed controller depends on the value of control parameters, gravitational search algorithm (GSA), and particle swarm optimization (PSO) techniques are used to optimize these parameters in order to achieve a predefined system’s performance. In respect of system’s performance, it is evaluated based on the tracking error present between reference inputs transferred to the system and the system output. This is followed by verification of the efficiency of the designed controller in simulation environment under various values, with and without the inclusion of external disturbance. It can be seen from the simulation results that the MSMC with PSO exhibits a better performance in comparison to the performance of the similar controller with GSA in terms of output response and tracking error.
Flow analysis of centrifugal pump using CFX solver and remedies for cavitatio...IJERA Editor
In this scholarly thesis pertinent to the working of centrifugal pump, a CFD solver namely CFX is employed in order to simulate fluid flow characteristics with well-defined constraints and boundary conditions defining the problem. Stringent solid model is meticulously prepared encompassing the present day usage and constructional features of a centrifugal pump and is constrained with various boundary conditions having fixed domain in order to evaluate plots and results. To spearhead and facilitate this analysis program a numerical approximation tool with high degree of convergence rate called ANSYS 15.0 software is used. The ASNYS software avoids tedious calculations presumably impending in the design procedure and uses ultimate numerical tool to approximate the solution of the partial differential equations associated with continuity, momentum and energy phases of a flow problem in a 3-D model. This exquisite feature of ANSYS enables designer to optimize the design procedure in an iterative manner based on the final plots of post-processing phase. In addition, the scholarly writing also constitutes the appraisal of the most debilitating and painstaking problem retarding the efficiency of the centrifugal pump known as cavitation. Possible remedies for overcoming this problem will be indirectly inferred from the various plots and figures derived from the post-processing phase of the design process.
Parametric study of a low cost pneumatic system controlled by onoff solenoid ...eSAT Journals
Abstract Expensive proportional valves are dominantly used in pneumatic positioning systems even with low demanding accuracy
positioning tasks, which deprive pneumatic systems from its economical advantages. Thereby, using low cost on/off solenoid
valves instead of proportional valves has been a topic of research in the last decades. In this paper, a parametric study is
conducted to investigate the effect of using low-cost 3/2 internally pilot on/off solenoid valves to control a double acting cylinder
and study the system nonlinear response to on/off and PWM input signal. Matlab ® Simscape library is used to model and
simulate the system. The model is validated though experimental measurements of the system behavior. The model is used to study
and decrease the nonlinear pressure response associated with the cylinder chambers in addition to the evaluation of the dead
zone and operating range of the on/off solenoid valve when operated with PWM signal. The results show that using a meter-in
flow control and having a near constant cylinder back pressure can reduce the nonlinearity. An orifice of 1e-6 m2 can reduce the
pressure variation by 80% but increase the transient time. Connecting an accumulator with 1 liter volume can result in 50%
reduction in rod side pressure variation. The model has been used to predict the PWM parameters as well. It has been found that
the most suitable parameters for this valve are 20 Hz and duty cycle from 12 to 65%. These results encourage going further with
controlling a pneumatic position system using low-cost control valves and a simple controller.
Keywords: Pneumatic Control, PWM, On/Off Valves, Simscape, Matlab
In chemical processing industry the pressure inside the vessel is increase due to many reasons. An
important responsibility of a chemical plant designer is to make sure that a plant under design, can be operated
safely, it is provided with primary, secondary safety arrangement. One of the dangerous situations that can be
arises during operation inability of a system to a pressure higher than that for which it was designed. With
designing pressure safety release valve for inside vessel pressure, should be giving priority to mechanical systems
to release inside pressure. The reasons are many for increase/exceed inside pressure. Most flow applications
require regulating the flow of liquid, and usually the parameter of concern is the pressure. This paper focuses on
the review on design of self regulating pressure valve by using transient finite element analysis. There are many
authors work on this pressure valve. This paper includes study of various papers related to self regulating pressure
valve. In this project focus on exchange of liquid between two chambers, where in it is required that flow be shut
off when a certain pressure is reached .Electronic valves are available, however the intent of this design project is
have a total mechanical system, which has an in built response mechanism.
The need for high pump performance and efficiency continue to encourage the study of flow between two parallel co-rotating discs in multiple discs pump or turbine. Therefore, this study entails the design, construction and CFD simulation of a 3D Tesla pump model axisymmetric swirling flow in order to enhance the understanding of Tesla pump for future development.
Method of solution entails designing and construction of a small prototype tesla pump and then using the design geometry and parameters to design and perform numerical simulation. The results of the numerical simulation were then analyzed.
The result obtained indicates static pressure to have minimum value of -4.7791Pa at the outlet and 13.777Pa at the pump inlet and with velocity magnitude having minimum velocity of 0.00m/s and maximum velocity of 4.12m/s. The strength of the velocity was seen to be very high at the pump outlet. The analysis radial velocity showed minimum value of -0.508m/s and maximum value of 3.981m/s with the radial velocity vector being concentrated at the discs periphery and outlet.
Model simulation results exhibited smooth pressure and velocity profiles. With the 3D simulation all flow variables are able to be predicted.
The need for high pump performance and efficiency continue to encourage the study of flow between two parallel co-rotating discs in multiple discs pump or turbine. Therefore, this study entails the design, construction and CFD simulation of a 3D Tesla pump model axisymmetric swirling flow in order to enhance the understanding of Tesla pump for future development.
Method of solution entails designing and construction of a small prototype tesla pump and then using the design geometry and parameters to design and perform numerical simulation. The results of the numerical simulation were then analyzed.
The result obtained indicates static pressure to have minimum value of -4.7791Pa at the outlet and 13.777Pa at the pump inlet and with velocity magnitude having minimum velocity of 0.00m/s and maximum velocity of 4.12m/s. The strength of the velocity was seen to be very high at the pump outlet. The analysis radial velocity showed minimum value of -0.508m/s and maximum value of 3.981m/s with the radial velocity vector being concentrated at the discs periphery and outlet.
Model simulation results exhibited smooth pressure and velocity profiles. With the 3D simulation all flow variables are able to be predicted.
Design of Industrial Electro-Hydraulic Valves, New ApproachIJERA Editor
A fully flexible valve actuation systems are being under consideration as an enabling technology for advanced internal combustion engine concepts. Electro-hydraulic valve actuator systems are being considered as a dominating variable valve technology. Compared to the servo control system, the system using a proportional valve has the advantages of low price, high anti-pollution ability and high reliability. Unlike existing electromechanical or servo actuated electro-hydraulic valve actuation systems, precise valve motion control is achieved with an internal feedback mechanism. This feedback mechanism can be turned on or off in real-time using simple two state valves which helps reduce the system cost and enables mass production.
Conceptual Designing and Numerical Modeling of Micro Pulse Jet for Controllin...CSCJournals
A conceptual design and numerical model of Micro Pulse Jet has been developed to investigate the flow separation. This valve is designed to generate the stream line vortices to suppress the flow separation by enhancing the mixing of the flows between free stream and separated flow of the boundary layer through pitched jet orifice of very small width. This paper describes not only the conceptual modeling of Micro Pulse Jet but also presenting the numerical analysis and results of steady and unsteady pulse of micro jet. The unsteady pulse of the valve is simulated by the periodic inlet boundary condition through mathematical model. A 2-D ramp with 20 degrees divergence is selected. The divergence of the lower wall of the ramp is large enough to produce a strong adverse pressure gradient causing the boundary layer to separate. A jet orifice is introduced at the upstream of the divergent portion of the ramp and the effect of steady and unsteady jet is analyzed. The main inlet boundary condition is almost of 0.2 Mach. The jet amplitude is characterized by the velocity ratio (Vj/V∞) in between 0 to 5 and the jet pulse frequency is varying between 0 to 100 Hz. A comparison between the steady and unsteady Micro Pulse jet is also done, which indicates the mass flow requirement for pulse micro jet is reduced significantly as compare to the steady jet for the flow separation control.
REVIEW OF FLOW DISTRIBUTION NETWORK ANALYSIS FOR DISCHARGE SIDE OF CENTRIFUGA...ijiert bestjournal
A computational fluid dynamics (CFD) analysis has been conducted to find the pressure losses for dividing and combining fluid flow through a junction of discharge system. Simulations are performed for a range of flow ratios and equations are developed for pressure loss coefficients at junctions. A mathematical model based on s uccessive approximations then would be employed to estimate the pressure losses. The proposed CFD based strategy can be used for the analysis of all the three pipe branches of s ome diameter are selected along with equal length so that only the effect of bend angle can be st udied. The effect of bend angle,pipe diameter,pipe length,reynolds number on the resistan ce coefficient is studied. The software used is CATIA for modeling and ANSYS fluent for analysis purpose.
Butterfly valves are widely used in hydro power plants to regulate and control the flow
through hydraulic turbines. That’s why it is important to design the valve in such a way that it can give
best performance so that optimum efficiency can be achieved in hydraulic power plants. Conventionally
that the models of large size valves are straight in the laboratory to determine their performance
characteristics. This is a time consuming and costly process. High computing facility along with the use
of numerical techniques can give the solution to any fluid flow problem in a lesser time. In this research
work flow analysis through butterfly valve with aspect ratio 1/3 has been performed using
computational software. For modelling the valve ICEM CFD 12 has been used. Valve characteristics
such as flow coefficient and head loss coefficient has been determined using CFX 12 for different valve
opening angle as 30°,60°,75°, and 90° (taking 90°as full opening of the valve) for incompressible fluid.
Value of head loss coefficient obtained from numerical analysis has been compared with the
experimental results.
Study on a linear relationship between limited pressure difference and coil c...ISA Interchange
On/off solenoid valves with PWM control are widely used in all types of vehicle electro-hydraulic control systems respecting to their desirable properties of reliable, low cost and fast acting. However, it can hardly achieve a linear hydraulic modulation by using on/off valves mainly due to the nonlinear behaviors of valve dynamics and fluid, which affects the control accuracy significantly. In this paper, a linear relationship between limited pressure difference and coil current of an on/off valve in its critical closed state is proposed and illustrated, which has a great potential to be applied to improve hydraulic control performance. The hydraulic braking system of case study is modeled. The linear correspondence between limited pressure difference and coil current of the inlet valve is simulated and further verified experimentally. Based on validated simulation models, the impacts of key parameters are researched. The limited pressure difference affected by environmental temperatures is experimentally studied, and the amended linear relation is given according to the test data.
Optimization of Modified Sliding Mode Controller for an Electro-hydraulic Act...IJECEIAES
This paper presents the design of the modified sliding mode controller (MSMC) for the purpose of tracking the nonlinear system with mismatched disturbance. Provided that the performance of the designed controller depends on the value of control parameters, gravitational search algorithm (GSA), and particle swarm optimization (PSO) techniques are used to optimize these parameters in order to achieve a predefined system’s performance. In respect of system’s performance, it is evaluated based on the tracking error present between reference inputs transferred to the system and the system output. This is followed by verification of the efficiency of the designed controller in simulation environment under various values, with and without the inclusion of external disturbance. It can be seen from the simulation results that the MSMC with PSO exhibits a better performance in comparison to the performance of the similar controller with GSA in terms of output response and tracking error.
Flow analysis of centrifugal pump using CFX solver and remedies for cavitatio...IJERA Editor
In this scholarly thesis pertinent to the working of centrifugal pump, a CFD solver namely CFX is employed in order to simulate fluid flow characteristics with well-defined constraints and boundary conditions defining the problem. Stringent solid model is meticulously prepared encompassing the present day usage and constructional features of a centrifugal pump and is constrained with various boundary conditions having fixed domain in order to evaluate plots and results. To spearhead and facilitate this analysis program a numerical approximation tool with high degree of convergence rate called ANSYS 15.0 software is used. The ASNYS software avoids tedious calculations presumably impending in the design procedure and uses ultimate numerical tool to approximate the solution of the partial differential equations associated with continuity, momentum and energy phases of a flow problem in a 3-D model. This exquisite feature of ANSYS enables designer to optimize the design procedure in an iterative manner based on the final plots of post-processing phase. In addition, the scholarly writing also constitutes the appraisal of the most debilitating and painstaking problem retarding the efficiency of the centrifugal pump known as cavitation. Possible remedies for overcoming this problem will be indirectly inferred from the various plots and figures derived from the post-processing phase of the design process.