Mavris, Dimitri N.

Osburg, Jan

Scholarly Materials And Research @ Georgia Tech

1Hypersonics Research at ASDLPrincipal Investigator: Dr. Dimitri Mavris, dimitri.mavris@ae.gatech.eduResearch Engineer: Dr. Jan Osburg, jan.osburg@asdl.gatech.edu2OverviewRASAC: First-order hypersonic vehicle sizing codeDesign projectsSupport of TBCC analysis effortDesign of morphing hypersonic strike vehicleNew toolsHigh-Mach aerodynamics analysis environmentInteractive 3D trajectory visualization3Objective: rapid-turnaround hypersonic and launch vehicle modeling, sizing, simulation and analysisPossible alternative approaches:Creation of meta-models of available legacy codes− Ineffective for high order and discontinuous design spaces with several variables − Does not enable “apples to apples” comparison− Introduces unknown assumptions from legacy codesParallel computing with actual legacy codes− Computational cost prohibitive− Code bugs/peculiarities− Does not enable “apples to apples” comparison− Still unknown assumptions from legacy codesCreation of a new architecture selection approach and development of a new launch vehicle sizing and synthesis model− Use of top-level disciplinary models − “Apples to apples” comparison − Faster computation time− Assumption: Lower fidelity models can still properly represent the design space of launch vehicles for architecture selection purposesRASAC First-Order Code4RASAC: CapabilitiesTurbojet TBCC RamjetVertical takeoffHorizontal takeoffAirbreathing trajectoryRocket trajectoryRocketLifting-bodyCylindricalAll-bodyAirbreathingboosterWinged-bodyCylindricalCylindricalCylindricalTrajectoryPropulsionAerodynamicsWeightRapid Access-to-Space Analysis Code (RASAC)5ResultsRASAC: Code StructureMatlab-basedInclude 5 disciplines, a geometry module and a mission module•Subsystem cost and mass•Recurring & development costs•Payload massTrajectoryPropulsionAerodynamicsWeightEconomicsGeometry&MissionComputation time drivers6Support of aTBCC Vehicle Analysis EffortAerospace Systems Design LaboratoryGuggenheim School of Aerospace EngineeringGeorgia Institute of TechnologyAtlanta, GA, 30332-0150Principal Investigator: Dr. Dimitri N. Mavris (dimitri.mavris@ae.gatech.edu)Point of Contact: Dr. Jan Osburg (jan.osburg@asdl.gatech.edu)Research Team: Frederic Villeneuve, Irian Ordaz, Bjorn Cole7Generic Mission1. Takeoff2. Climb/Accelerate to Mach 75. Dash outMach 7, 100 nm6. Cruise Back, 650 nm9. Landing4. Turn 180 Degrees at Mach 7, best altitude8. Loiter 20 min.3. Dash in - Mach 7, 750 nm7. Descent8Design Space Exploration ApproachDesign Space ExplorationVehicle GeometryDesign of Experiments(Engine Parameters) Hypersonic Strike MissionOverall Design of ExperimentsDesign space exploration approach for the determination of the optimal engine and mission parameter settings9Design Space ExplorationEngine Settings vs. Mission RequirementsEach engine setting tested for Fractional Factorial DoE of mission requirementshttp://www.geocities.com/ResearchTriangle/System/3737/imgs/section3394.gif10Modeling & SimulationDesign Structure MatrixTrajectory(RASAC)Weight & Volume(MER's)Aeroheating(MINIVER)Propulsion(P&W)Aerodynamics(MUSTANG)Geometry(Vehicle SketchPad)11Geometry: Vehicle Sketch Pad (VSP)3D Drawing of the baseline vehicle Table: Vehicle parameters and dimensionsTop FrontSide Isometric12PropulsionFlight envelope of low- and high-speed enginesProposed High & Low Speed Flight Envelope020,00040,00060,00080,000100,000120,0000.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0Mach NumberAltitude, ftLow Speed Engine High Speed Engine Part Power Q  @ 500 Q @ 1000 Q @ 1,50013PropulsionDrag and thrust calculation workflowTurbojetEngine DeckRamjetEngine DeckEngine SettingsRam and spillage drags Adjusted gross thrustTrajectory SimulationInlet drag computation procedureNozzle net force computation procedure14Over-Under Geometry Adapted to VehicleComparison with Original GT Vehicle to Define Nozzle A9 AreasOriginal GT Architecture better suited to dual TJ InstallationModified Architecture to Satisfy Single TJ StudyA9 for RJ is total X-SecA9 for TJ is also total(Conservative)A9 is total projected area => No boattail drag areaRJ FlowpathTJ FlowpathEquivalent to configuration w/dual 0.707-Scale TJ’sFor each solution:15Aerothermal Analysis ProcessProcess Diagram of the Aerothermal AnalysisMINIVERRUNMINIVER PROCESSSTREAMVSP GEOMVehicle Sketch Pad Geometry16Aerothermal Analysis ProcessMINIVERRUNMINIVER PROCESSSTREAMVSP GEOM• A sample streamline or contour for the fuselage centerline from the STREAM script• These are then integrated into the MINIVER input file• The vehicle is discretized into a number of these streamlines in the spanwise direction and mirrored on the other side assuming symmetry of the vehicleHypersonic Vehicle (Centerline)-0.2-0.15-0.1-0.0500.050.10.150.20 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1X/LZ/LUpper (P&W inlet)Low er (P&W inlet)17Aerothermal Analysis Process‘RUNMINIVER’Executes automatically MINIVER with all the input files generated by STREAM Generate an input and output file for each streamline‘MINIVER’Aerothermal analysis code developed by NASAMINIVERRUNMINIVER PROCESSSTREAMVSP GEOM18Aerothermal Analysis: Output DescriptionMINIVERRUNMINIVER PROCESSSTREAMVSP GEOM‘PROCESS’Post-processing script gathering the …Heatload – Contains the average, total, peak, and minimum heatload as a function of time throughout the mission.Heatrate – Contains the average, total, peak, and minimum heatrate as a function of time throughout the mission.Results – Contains the detailed aerothermal results (heat coefficient, heatrate, and heatload) for each point (lengthwise and spanwise) on the vehicle at each point in the mission.Heatload_Loc – Contains the peak, minimum heatload values and where they are located on the vehicle throughout the mission.Heatrate_Loc – Contains the peak, minimum heatrate values and where they are located on the vehicle throughout the mission.19Aerothermal Analysis Validation Case: X-34X34 Mission: Mach01234567890 100 200 300 400 500 600 700 800 900Time, secMachX34 Mission: Alpha0510152025300 100 200 300 400 500 600 700 800 900Time, secAlpha (deg)X34 Mission: Altitude0501001502002500 100 200 300 400 500 600 700 800 900Time, secAltitude (kft)X34 Mission: Stagnation Point Heatrate-10-50510152025300 100 200 300 400 500 600 700 800 900Time, secHeatrate (btu/sft-s)MINIVER: Tangent wedgeCFD: EulerX-34 TrajectoryComparison of resultsX34 Mission: Stagnation Point Heatload050010001500200025003000350040000 100 200 300 400 500 600 700 800 900Time, secHeatload, btu/sftMINIVER: Tangent wedgeCFD: Euler20Design Space ExplorationMission Design of ExperimentsFractional Factorial360 runs & 8 variablesVariables and settingsSimulation ResultsRunning time: ~ 4hrs~40% of runs have closed vehiclesMission Parameters included in the DoE21Design Space ExplorationMultivariate analysis plotMission parametersResponsesTOGW < 60,000 lbsTOGW > 100,000 lbs22ResultsMultivariate AnalysisLatin Hypercube (100 runs)Constants:W/S = 150 lb/ft2Variable Ranges1. Mach TJ shutoff: [3, 4]2. Mach RJ start : [2, 3]3. Dash Mach : [5, 6]4. T/W : [0.8 1.2]5. A9/Acap : [1, 1.5]Limits:Wfuel > 30 klbs (blue)Wempty > 40 klbs (green)TOGW > 70 klbs (red)23Hypersonic Persistent Configuration (HyPer) Development WBI/AFRL Sponsored ResearchPoints of Contact:Dr. Jan Osburg (jan.osburg@asdl.gatech.edu)Dr. Peter Hollingsworth (peter.hollingsworth@ae.gatech.edu)24HyPer: MissionDash/strike at up to Mach 5, loiter/cruise/refueling subsonicSizing (ModelCenter/FLOPS) based on “rubber mission,” shown belowSponsor desires morphing configurationTake OffClimbCruise InOptionalRefuel #1Loiter Dash Climb and AccelDash CruiseTurnEscapeDropOptional Refuel #2Return25FLOPS Sizing EnvironmentDesigned to converge weights input into FLOPS and computed from weights modelAerodynamic RSEs are integrated in loopIncorporates propulsion tablesAble to run alternate geometriesFolding wingtips (XB-70 style)Variable-sweep wing26Geometry – One Configuration27Family of Solutions – Thousands of RunsSample results shown –other dimensions of results also collected (e.g. gross weight)Removing designs above or below threshold values will show what freedom remains in other dimensions of design/solution spaceOne goal of approach is to find how much design freedom a given decision (e.g. requesting dash time to be less than 20 minutes) restricts28Solution Space 1 – Feasible Pareto Optima29Solution Space 2 – Filtering on Dry Weight30Solution Space 3 – Projection of Dry Weight into Other Dimensions31Payload Release Analysis (Mach 5)1 24332OverviewRASAC: First-order hypersonic vehicle sizing codeDesign projectsSupport of TBCC analysis effortDesign of morphing hypersonic strike vehicleNew toolsHigh-Mach aerodynamics analysis environmentInteractive 3D trajectory visualization33CoRVET Geometry ModelerExcel/VBA tool to specify concept geometries for downstream analysesExcel portion useful for defining custom variables and higher level design parameters (ramp angles, wing aspect ratios, vehicle fineness ratios, etc.), as well as direct linkage to other spreadsheet analysesVBA portion outputs text files appropriate to aerodynamics codes of UDP and SHABPAutomatically derives interference shells from fuselage definition, trims wings and vertical tails to match shellAdds appropriate features such as specifying both a slender body and a standard body (for viscous analysis)Roughly 5,000 lines of VBA to write UDP and SHABP geometriesα1 α2β1 β2 β3 β4γ1Inlet Flow pathhcaphnozγ2DaftDfwdDmaxΛ LE wingΛ LE CanardΛ LE V Tail Concept to CoRVETCoRVET to *.hrm file, UDP input deck34MUSTANG Aerodynamics ToolMUSTANG incorporates freeware enhancements to SHABP developed inASDL (triSHABP and trifrict tools), UDP from APAS-II and SHABP Mark VCustom interpreters developed to enable UDP execution without APASRead in plot conditions from text fileCoRVET generates APASIN decks from scratchInterpreters parse binary *.plot files from APAS into text decksTriSHABP creates text file inputs for SHABP from triangulated *.hrm geometry specificationsResults from aerodynamics tools are collected and incorporated into a single aerodynamics deckBridging functions available to smooth results from one software to anotherEmpirical transonic relationships applied to wave drag portion of UDP output to find Mcrit and fill in between Mcrit and M = 1.0Run time: about 15 seconds per case on average desktop PCAbout 30 minutes to run all 96 M, h, AoA combinations35MUSTANG ModelCenter Environment1) CoRVET2) condin writer3) apasin / condin / UDP / apasdat4) trisurf5) triSHABP6) Data parser / merger12345636MUSTANG: Principles of UDPLinear analysis codeSums contributions from lift-induced vortex drag, lift-induced wave drag, volume wave drag, flat-plate viscous drag and form drag contributionsVortex panel method enhanced by boundary conditions from slender body calculations to account for fuselagesAnalyses applied to components of configuration depending on their typePhysics highly simplified for feasible compute times circa 1970 – now extremely rapid analysisθμ Σδ37MUSTANG: Principles of SHABPSupersonic/hypersonic impact codeAll calculations done on the basis of a deflection angle between free-stream flow and model element normalsLarge variety of formulas available to account for various importance of flow phenomenaFormulas with conical/wedge flow analoguesSemi-empirical formulasNormals are all that matterOriginally drawn up as quadsCan be fed triangular elements to better represent geometries and avoid redundant elements via TRISHABP38Trajectory Mapping Tool (TRAM)Java tool which visualizes POST trajectoriesTRAM allows for Mercator projections colored by the values of POST output file variablesUser can quickly browse a 2D pictorial representation for each POST output variableData may be exported to a kml (Google Earth) formatAllows for interactive 3D trajectory renderings using Google Earth39TRAM: Leveraging Google EarthOpening the kml file with Google Earth will show the POST trajectory over a high-resolution and zoomable “Earth”, with an intuitive, highly interactive user interfaceUser selects which output variable coloration will be passed to the exported kml fileKml generation can be either run either manually or automaticallyThe final approach for a return trajectory is shown below40TRAM: Display of Additional VariablesEach trajectory point in the KML file contains3D coordinates that determine the position of the trajectory point in Google EarthData for a variable selected by the user during KML generation in TRAM that determines the color of the trajectory point in Google EarthIf available in the POST file these key variables are displayed when a trajectory point is clicked on− Velr, Mach, Gdalt, Gammar, alpha, Weight, Etal, Dynp, Lift, Drag, Thrust, Effisp, videal, Dprng1

Hypersonics Research at ASDL

https://smartech.gatech.edu/bitstream/1853/25170/1/ASDL_Hypersonics_Overview_2007-02-26.pdf

Hypersonics Research at ASDL

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