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Chasing the land speed record using a fighter jet turned into a car.

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Darren Grove - aerodynamicist for the all-volunteer project North American Eagle - a project to break the world's land speed record using a jet-powered car, talks about his current project to reduce …

Darren Grove - aerodynamicist for the all-volunteer project North American Eagle - a project to break the world's land speed record using a jet-powered car, talks about his current project to reduce drag in the after wheels and axle using computer simulations.

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  • Hi my name is Darren Grove and I am an Aerodynamics Engineer for the North American Eagle, a car that will attempt to break the current land-speed record of 763 mph. Today’s talk will be about how EnSight CFD software has helped the project with it’s computational analyses for aerodynamic design.
  • Before I begin I would first like to say…Although I am employed by the Boeing company, this project is not sponsored, funded, nor associated with the Boeing Company. My work on this project is outside of Boeing on a consulting bases.
  • The outline of the presentation will lead you through the history of Land-Speed record accomplishments2) Give an overview of the North American Eagle project through the introduction of the owner and project director combined with a video of the car and some unique technological features. 3) Talk about some of the logistical and technical challenges of breaking the land-speed record.4) How EnSight software is being used in the design and analyses process.5) Followed by some results, future planned work to optimize the cars performance, and summary.
  • For over 100 years now people have been pushing the limits of wheel driven vehicles to higher and higher speeds. This chart shows the progression of increased speed over the past 100 years. The lower left hand side of the chart shows the early years with piston type engines. Note that in the early years from around 1910 to 1927 the speed of the car did not increase by much, but from 1930 to 1950 we see a steady increase in top speed achieved. This was contributed by both the increase power of the engines and advances in aerodynamic streamlining the car. In order to go even faster, using jet powered cars were conceived and built starting in the late 1960’s.In the years between 1967 and 1968, a car named Spirit Of America was successful in reaching 600 mph (965 km/h). This was quite an achievement because of the unknown risks could not be simulated by CFD at that time, and the cars were crossing into the transonic speeds were shock were forming around the cars. The next 25 years saw only few attempts to keep reaching higher speeds, mostly by the British, and in 1997, they were the first ones to break the sound barrier reaching a top speed of 763 mph (1227 km/h)
  • Here are some of the record holders showing their cars and top speeds. Note that tires are made of rubber Also note the aerodynamic shaping
  • Ed Shadle, the man in the image on your left is the Owner, Driver, an Project Manager. He a former IBM Manager, specializing in disaster recovery computer systems for the Northwest region of the United States. After retiring from IBM in 1997, he formed his own company called “North American Eagle” with the mission to bring back the world land speed record to North America, currently held by the British. He started building cars at the age of 14 and annually competes in high-speed events at the famous Bonneville Salt Flats in the United States. Keith Zanghi, the man in the image on your right, is the Director of Operations. He is former drag car racer. His responsibilities include the project logistics and overseas the daily operations. These man, with a team of volunteers work weekends trying to build a jet powered car that will not only break the sound barrier, but bring the title back to North America. Let us take a look at a 5 minute video showing some of the history of how the car became a reality, and some technologies developed in this project.
  • A few key technologies are being developed and built to support our mission. 1) One is the electro-magnetic breaking system needed to help stop the car in a short distance due to finite length of the dry lake beds in which we run the car.2) Another is the aluminum wheels designed to with-stand the enormous centrifugal stresses due to the extreme rotational speeds.3) A parachute system that has the lanyard chord design to with-stand the tensional forces up to a deployment at 700 mph. Although I would feel sorry for the driver should he need to use it at this speed. 4) The CFD is playing a major role in the design and optimization of the car aerodynamic shaping and analyses of the stability and control. The first step we took was to use advanced software scanning tools to construct a 3D surface model of the car’s features using photogrammetrics. Then converted that data to a 3D solid model, and read that into POINTWISE to build the CFD mesh. After running the solutions EnSight post processing tool suite was used to gain a better understanding of the flow field.
  • Lets talk about some of the challenges that we face in attempting to break the record.Form a logistical aspect When & Where plays a major roll in logistic. The dry lake beds we run the car on support only a few month window of opportunity to run the car due weather conditions from high winds, to rains, to temperatures that affect the dry lake condition. Travel arrangements - time off from work, hotel availability, food Need Trained personnel Support equipment – Tools, supply parts, start cart for the engine, large trucks to transport the equipment.
  • Before I show any of the EnSight analyses, I would like to explain a little about transonic aerodynamics and what we call “Shocks”.A shock wave (also called shock front or simply "shock") is a type of propagating disturbance, characterized by an abrupt, nearly discontinuous change in the characteristics of the medium. Across a shock there is always an extremely rapid rise in pressure, temperature and density of the flow.When a shock wave passes through matter, the total energy is preserved but the energy which can be extracted as work decreases and entropy increases. This, for example, creates additional drag force on aircraft with shocks, called wave drag.
  • Here is an image made with EnSight software from a 700 MPH (1126 km/h) solution. This image shows three distinct regions of sonic flow “shocks” at the front, mid, and aft end of the car. Transonic shocks product large pressure gradients that can effect the vehicles performance, stability, and control.
  • Why CEI EnSight was chosen for the NAE project was simple.The GUI has very easy to use with an intuitive layout that separates icons into groups of key action commands. The icons at the top are used to choose what action you want to perform on the data. For instance, making movies, using the calculator to perform operations on the data, plotting the data just to name a few. The parts ID window can be used for picking a part to work on. Multiple parts can be grouped together to simply the search and execution on a group or a part within the group. The icons on the left are controls for display control of parts, view ports, legends, and plots. The icons at the bottom for rotational, translational, and zooming control. EnSight have a very powerful tool set to perform interrogation of the solutions.Performing dataset queries, making movies, plotting data, generating iso-surfaces (constant value) and particle traces are simply done through a few clicks of a button. Import of many cell types and solution formats are supported Recording of commands during interactive sessions and then playback it supported. And support of Python Scripting language can be used to post-process large amounts of data, increasing productivity.
  • Here a just a few samples of the tools. The image on your left shows a query of the NAE dataset with the max and min dimension in X,Y,Z, and the types and number of cells of the grid.The middle image shows the GUI for EnSights calculator. It has many predefined functions and the capability to generated your own custom functions.The image on the right is a plot of the pressure along the centerline of the car for both upper and lower surface. The EnSight plotter has an great deal of annotation capability for both steady state and time accurate data.
  • This image shows the many different cell types in a computational domain that can be read in by EnSight.
  • Before I go into more details about the grid and solutions, I think it’s important to understand that the grid and solutions you are about to see were run on computer systems in my house, and not on clusters.We received two donated High-End LENOVO C20 workstations. I linked the two workstations together with a 1GB network switch. I have 3 primary CFD software codes loaded, for grid generation – EnSight, for the flow solver – Metacomp’s CFD++, and CEI’s EnSight Suite of tools.Each workstation contains 48 GB of RAM, has 2-processors with 6 cores each for a total of 12 compute nodes. With both workstations linked together I have 96 GB of RAM and 24 compute nodes. With this hardware, I am limited to a max grid size of about 12 million per workstation. Thus I have to be careful of how I make my grids.
  • This image details some of the numerical modeling and selection of the Boundary Conditions to simulate real world conditions as best as possible.The inlet was modeled with mass flow to better simulated the airflow in-and-around the inlet to reduce the likelihood of mass-flow spillage (chocked inlet). Also, this phenomena would lead to higher drag. The exhaust velocity was modeled to simulate and thrust, and reduce separation and recirculation of the airstream, which again, may cause an increase in drag. The ground plane was modeled so we could get the effect of shock/ground plane interactionsThe image in the upper right hand corner shows how the wheel is actually inserted into the ground, simulating real world scenario. The car weights 13,700 lbs ( 6214 kg). Since we are running on dry lake beds, the soil is somewhat soft, so the car will sink in the ground slightly.
  • This is an image of a 700 mph (1126 km/h) using Iso-surfaces and Mach function to extract featuresAgain, this image show 3 distinct regions of shocks that form above and below the car. Note that in this image I display a region of iso-surfaces with Mach =1. The flow is sonic everywhere inside these “Mach” cones. Not the small shock on the canard. The car surface is colored by Pressure. The ground plane is also colored by Mach. I would like to show you movie now that was generated with EnSight, and will display some particle traces as the flow through the shock regions and around canard, inlet, and aft body of the car.
  • As the car is set up today, the aft suspension system has no fairings and causes a lot of flow separation and thus drag on the car. The largest drag producer of the car is the large flat iron that is aligned normal to the oncoming flow. As the airflow tries to make its way around the beam, a large region of flow separation occurs as can be seen with the magenta color iso-surfaces. In addition, small regions of sonic flow appear, which one extends to the ground.
  • Python scripting is very powerful scripting language that can be used with EnSight to post-process large amount of data efficiently. The goal of the project is to make sure the car is safe and capable to meet our mission of breaking the current land speed record.Many CFD conditions will need to be run and analyzedPYTHON scripting is used to automate the post-processing analysesto obtain the Force and Moment data and produce Charts, Images, and Tables of useful information.How it works:A set of python scripts resides in the users home directory (iso-surface.py, 3d_plots.py, etc…)The user will set their profile up to make sure it can find the “post_csh” shell script (inside the users home directory)The user must have the header.txt file in solution folder when they execute the “post_csh” script. This will call the header.txt file and execute any of the python scripts that the user has turned on. (Show the header.txt file)The python scripts will then generate a “data” and “post_images” folder and perform the specific operations set up in each python script. Then, depending on the python script, export force and moment tables (excel format too) to the data folder, and 3d plots, movies, and images to the post_images folder.
  • These plots are example of the title and 3-view plots that are created with the python scripts.
  • This chart shows a composite of 3 pie charts consisting of the shear, pressure, and total drag components for each of the car parts. These pie charts can be used to easily see which part is contributing the most drag for the given solution. In addition, a nice graph of the car showing the accumulated drag along the body of the car in the X direction shows how the drag spikes at the mid-brace. A table of the Drag Force is also displayed. This is a very useful chart when comparing multiple solutions to determine which car parts are most significant contributors to the drag force.
  • Likewise, this bar chart shows the lifting force contributions for each part of the car. Again with a table of lift forces due to pressure, shear. A sum of the totals along with the lift coefficients and percentages are also displayed.
  • Some of the questions we need to ask is:Can we make our goal of breaking the land speed record as the car sits today?How do we know the car will stay on the groundWhat are the impacts of the ground proximity to the car with shocks?Is there anything we can do to clean up the car aerodynamically? This chart of Force vs Speed of the car shows some of those affects.This chart plots both the drag and lifting force as a function of speed. Starting with the drag story, we first ran the car with the suspension. The results are this blue line here. We then had to adjust that data for rolling resistance and as you can see we can only get to about 690 mph. The total thrust of the car is plotted by this line. We then took off the suspension and re-ran the solutions with both a ground plane and without a ground plane. The difference is substantial between with and without the suspension system as can be seen by this delta. From these plots, it appears we may be able to make our goal if we can aerodynamically clean up the suspension.For the lifting force, the runs with the suspension shows an up/down variation with speed, but the ones with out he suspension shows less sensitivity with speed. However, the car weights 13,700 lbs, and none of the forces approach this magnitude, showing the car should stay on the ground.
  • Transcript

    • 1. “Project North American Eagle” Challenging the Land-Speed Record Using EnSight Software for Aerodynamic Design Darren Grove Aerodynamics Engineer 11/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 2.  Conflict of Interest Statement. Although I am employed by the Boeing company, this project is not sponsored, funded, nor associated with the Boeing Company. My work on this project is outside of Boeing on a consulting bases. 2CEI Users Conference 2011 - Tokyo Japan11/09/2011
    • 3. 10/23/2011 3CEI Users Conference 2011 - Tokyo Japan11/09/2011
    • 4. 11/09/2011 CEI Users Conference 2011 - Tokyo Japan 4 482 724 965 1223 1448 KM/H
    • 5. 11/09/2011 CEI Users Conference 2011 - Tokyo Japan 5 413 mph / 664 km/h Tom Green 622 mph / 1001 km/h Gary Gabelich 576 mph / 927 km/h Art Arfons 633 mph / 1019 km/h Richard Noble 600 mph / 964 km/h Craig Breedlove 739 mph / 1189 km/h Stan Barrett
    • 6. 10/23/2011 6CEI Users Conference 2011 - Tokyo Japan11/09/2011
    • 7. 10/23/2011  Advanced Technologies  Revolutionary Breaking System  High Speed Wheel Design  Treated Aluminum  Capable up to 15,000 RPM  Parachute System  Deployable up to 700mph  CFD Digitize Mesh EnSight 7CEI Users Conference 2011 - Tokyo Japan11/09/2011
    • 8. 811/09/2011 CEI Users Conference 2011 - Tokyo Japan Logistical Technical
    • 9. 910/23/2011 VINAS Users Conference 2011 - Tokyo Japan TRANSONIC AERODYNANICS SHOCK FORMATION  A shock wave (also called shock front or simply "shock") is a type of propagating disturbance, characterized by an abrupt, nearly discontinuous change in the characteristics of the medium. Across a shock there is always an extremely rapid rise in pressure, temperature and density of the flow. This phenomena creates addition drag force on the vehicle known as “wave drag”. Image source: Wikipedia - http://en.wikipedia.org/wiki/Shock_wave a V M RTa
    • 10.  Transonic shocks product large pressure gradients that can effect the vehicles performance, stability, and control. 1011/09/2011 CEI Users Conference 2011 - Tokyo Japan Ground Plane Canard
    • 11. 1111/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 12. 1211/09/2011 CEI Users Conference 2011 - Tokyo Japan Plotter CalculatorQuery Dataset
    • 13. 1310/23/2011 VINAS Users Conference 2011 - Tokyo Japan Lecture 7 - Meshing http://www.bakker.org © André Bakker (2002-2006)
    • 14.  Computer Setup • Donated High-End LENOVO C20 Workstations • Linked together via a 1GB network switch • EnSight, Metacomp CFD ++, CEI EnSight installed • 48GB RAM / workstation • 2 - Processors (6 cores ) = 12 CPU’s available • Windows 7 Professional 64 Bit OS  Limitation • Max grid size ~ 12 million cells/workstation due to RAM memory limit, using CFD++ 1411/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 15. 1510/23/2011 VINAS Users Conference 2011 - Tokyo Japan Mass Flow-Thru Inlet Modeled Powered Exhaust Modeled Ground plane modeled – Inviscid surface tangency
    • 16.  700 mph (1126 km/h) case using Iso-surfaces and Mach function to extract features 1611/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 17. 1710/23/2011 VINAS Users Conference 2011 - Tokyo Japan Local pockets of sonic flow Magenta = iso-surfaces of separated flow Flat frontal area Large Drag Producer
    • 18. 10/23/2011 18CEI Users Conference 2011 - Tokyo Japan11/09/2011  The goal of the project is to make sure the car is safe and capable to meet our mission of breaking the current land speed record.  Many CFD conditions will need to be run and analyzed  PYTHON scripting is used to automate the post-processing analyses to obtain the Force and Moment data and produce Charts, Images, and Tables of useful information. Forces, Moments, Images, Ch arts, Tables Solutions Python Scripts Home/.ensight92 • Python scripts Solutions Folder • execute post_csh script • reads header.txt Creates • “data” Folder • Force & Moment Tables • “post_images” Folder • 3d plots, movies, images
    • 19. 1911/09/2011 CEI Users Conference 2011 - Tokyo Japan Title Page 3-View
    • 20. 2010/23/2011 VINAS Users Conference 2011 - Tokyo Japan
    • 21. 2111/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 22. Approximate Solution Run Times  For a 12 million cell grid, half body, about 16-20 hours/solution (one computer)  For a 24 million cell grid, full model, about 24 hours per solution (2 computers) 2211/09/2011 CEI Users Conference 2011 - Tokyo Japan NAE – half model # Tets # Pyramids # Prisms # Total cells % Cells Time (min) Before (Gridgen) 22,460,446 - - 22,460,446 - 12.4 After Recombination (PW) 7,018,396 65,154 5,391,558 12,475,108 55.5 5.2
    • 23. 2311/09/2011 CEI Users Conference 2011 - Tokyo Japan Mach=1.0 -10000 -5000 0 5000 10000 15000 20000 25000 300 350 400 450 500 550 600 650 700 750 800 850 900 Force-lbf MPH Force vs Speed (mph) FX FZ Max Thrust Max obtainable Mach=1.0 Car Weight Force Adjusted for RR FM_BVGP_FX FM_BVGP_FZ FM_BVFA_FX FM_BVFA_FZ Thrust ~ 18,500 lbs Goal F(carnard) = 0 deg (constant - relative to ground plane) Weight of Car ~ 13,700 lbs Total Drag Final Data - Adjusted for Car's Rolling Resistance Drag Delta (Suspension) GP effect
    • 24. 9/14/2011 2411/09/2011 Conceptual design Conceptual design Today’s Car CEI Users Conference 2011 - Tokyo Japan
    • 25.  CFD is being used to analyze and optimize the aerodynamics, Stability & Control of the North American Eagle.  CEI EnSight software was chosen for it’s excellent post-processing capability, tool sets, and robustness to analyze complex solutions.  The use of iso-surfaces and particle traces have been used to gain a better understanding the shocks and ground proximity effects.  PYTHON scripting language is being used to automate the post- processing of a large amount of CFD data, leading to a more efficient, productive, and repeatable processes. 2511/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 26. 10/23/2011 26CEI Users Conference 2011 - Tokyo Japan11/09/2011
    • 27. 2711/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 28. Backup Slides 2811/09/2011 CEI Users Conference 2011 - Tokyo Japan
    • 29. 2911/09/2011 CEI Users Conference 2011 - Tokyo Japan Time Speed Initialrollout ThrottleUp MaxThrust ThrottletoIdle Airbrakes Parachute ManualBraking Acceleration Deceleration 2 )( atVtXotX 2 )( atVotV
    • 30. 3011/09/2011 CEI Users Conference 2011 - Tokyo Japan 1 2 3 4 7 8 9 10 0,0,0 Reference 0,0,0 is located directly below tip of pitot tube on ground plane and at centerline of car Body Location Port # X (in) Y (in) Z (in) 1 79 0 .0 32.31 2 80.25 0 .0 16.37 3 129 0 .0 43.77 4 128.25 0 .0 10.86 5 238 23.71 36.0 6 243 0.0 64.04 7 262 23.77 36.0 8 286 0 62.37 9 286 20.0 48.0 10 288 23.6 24 11 332.5 5.0 36.0 12 332.5 42.69 36.0 13 346.5 42.74 36.0 14 388.5 41.0 36.0 15 497.25 27.93 48 16 524 28.0 48 14 1516 6 5 11 1213 Z=36” Z≈48”
    • 31. 11.00 mile Track MOBILE DAQ 1.00 m 1.00 m 1.00 m 2.50 m NTWK TWR 1 NTWK TWR 2 NTWK TWR 3 Ethernet Range Stand-off Distance 5.00 m 7.50 m 10.00 m WINDMILL CHARGE WINDMILL CHARGE BATTERIES GNSS REF Antenna Shadow North American Eagle Data Acquisition Range Layout
    • 32. 3211/09/2011 CEI Users Conference 2011 - Tokyo Japan Extruded Anisotropic Tetrahedral Layers
    • 33. 3311/09/2011 CEI Users Conference 2011 - Tokyo Japan  Multiple normal's help to refine cells around sharp corners. This helps capture flow field properties that otherwise might be missed when compared to single point normal's that can lead to large, more skewed cells.

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