POLITECNICO DI TORINO             I FACOLTA’ DI INGEGNERIA             TESI DI LAUREA SPECIALISTICA             IN INGEGNE...
Thesis activityPart of ESA’s Future Launchers Preparatory Programme hasbeen devoted to optimizing a long-term European roa...
The IXV Project       Technology platform        • Intermediate element of technology-effective and cost efficient Europea...
Experimental measurements           Mockup           • representative of external shape           • inertial properties   ...
Modeling methodology                          Solver                                       • Hyperview       • Hypermesh  ...
IXV numerical model         STRUCTURE                  MODELING       CONFIGURATION               ASSUMPTIONS             ...
Fluid numerical model                             MODELING       FLUID DESCRIPTION                            ASSUMPTIONS ...
Fluid numerical model           HORIZONTAL EXTENSION           • LimitedZ Acceleration -to                     front dimen...
Characteristic elements dimension                      Finest mesh   Sensitivity                       normal to     analy...
Fluid-structure interface                                   FLUID                                 STRUCTURE               ...
Boundary-initial conditions                        • Atmospheric pressure to water free                          surface  ...
Numerical - Experimental Correlation               All loadcases computed from 0 to 200 ms             FOURTH             ...
First Loadcase                   0.2        AX - COG                    0.1                     0                   -0.1 0...
Second Loadcase                    0.1        AX - COG                     0                          0   0.02   0.04   0....
Third Loadcase                   0.3        AX - COG                   0.2                    0.1                     0   ...
Third Loadcase        19 deg Sensor                        0.40                        0.30                        0.20   ...
Correlation results summary                                         model updating activity                               ...
Remarks and further developments                             Experimental                           numerical results     ...
Thanks for your attention17/17
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Studio sul comportamento strutturale di un veicolo da rientro atmosferico in fase di ammaraggio

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Studio sul comportamento strutturale di un veicolo da rientro atmosferico in fase di ammaraggio

  1. 1. POLITECNICO DI TORINO I FACOLTA’ DI INGEGNERIA TESI DI LAUREA SPECIALISTICA IN INGEGNERIA AEROSPAZIALEStudio sul comportamento strutturale di unveicolo da rientro atmosferico in fase diammaraggioRelatori• Prof. Giulio Romeo – Politecnico di Torino• Ing. Roberto Ullio – Thales Alenia SpaceCandidato• Maurizio Coltro
  2. 2. Thesis activityPart of ESA’s Future Launchers Preparatory Programme hasbeen devoted to optimizing a long-term European roadmap forin-flight experimentation with atmospheric re-entry enablingsystems and technologies.The IntermediateeXperimental Vehicle (IXV)project is the next core stepof this effort.This work has been developed within the IXV project and withclosed collaboration of TAS-I and ESA.Many thanks to ESA and TAS for their support. Thanks also to AltairEngineering for providing the software suite for the analysis.
  3. 3. The IXV Project Technology platform • Intermediate element of technology-effective and cost efficient European roadmap • Prepare future ambitious operational system developments with limited risks for Europe Project objectives • Design, development, manufacturing, on-ground and in-flight verification of autonomous European lifting and controlled re-entry system Critical technologies of interest • Advanced instrumentation for aerodynamics and aerothermodynamics • Thermal protection and hot-structures solutions • Guidance, navigation and flight control Success of IXV mission • Correct performance of re-entry • Safe landing and recovery with its experimental data1/17
  4. 4. Experimental measurements Mockup • representative of external shape • inertial properties • scale factors Physical quantities • accelerations • pressures Test facility • electromagnets to release vehicle • high frequency cameras • high pool dimension to perform impact2/17
  5. 5. Modeling methodology Solver • Hyperview • Hypermesh • Radioss • Hypercrash BLOCK V10 Preprocessor Postprocessor Explicit Suited for solution Drawbacks problems tecnique • short duration • high velocity • highly nonlinear nature3/17
  6. 6. IXV numerical model STRUCTURE MODELING CONFIGURATION ASSUMPTIONS External dimensions taken Fuselage into account components Bidimensional rapresentation of surfaces Flaps assembly Rigid body description RIGID BODY INERTIAL PROPERTIES Mass Jxx Jyy Jzz [kg] 27,82 1,17 4,52 4,314/17
  7. 7. Fluid numerical model MODELING FLUID DESCRIPTION ASSUMPTIONS Gas volume extension LAW37 Biphas ALE approach Liquid volume extension5/17
  8. 8. Fluid numerical model HORIZONTAL EXTENSION • LimitedZ Acceleration -to front dimensions Accelerometer T1064-63 (COG) avoid wave reflection VERTICAL EXTENSION • Limited in-deep dimensions to lighten fluid model WATER BASIN COMPARISON Deep water model Shallow water model 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 Horizontal 1,22 x 2,14 [m] 1,22 x 2,14 [m] Vertical Time [s] 0,8 [m] 0,4 [m] N Elements 335265 Deep Water Model 189317 Shallow Water Model CPU Time 8413 [s] 5077 [s]6/17
  9. 9. Characteristic elements dimension Finest mesh Sensitivity normal to analysis phenomenon 2D ELEMENTS 3D ELEMENTS 3D ELEMENTS (VEHICLE) (AIR) (WATER) HEIGHT 20 [mm] 20 [mm] 20 [mm] WIDTH 20 [mm] 20 [mm] 20 [mm] DEPTH / 10 [mm] 10 [mm] N ELEMENTS 3564 78324 2871887/17
  10. 10. Fluid-structure interface FLUID STRUCTURE INTERFACE TYPE18 SENSITIVITY STFAC GAP ANALYSIS Interface Activation PERFORMED stiffness distance PRESSURE PROBES • Single TYPE18 interface to INTERFACE represent sensors separately8/17
  11. 11. Boundary-initial conditions • Atmospheric pressure to water free surface WATER • DYREL dynamic relaxation for convergence BOUNDARY • Gravity load to water volume CONDITIONS • Lateral/bottom surfaces locked • FLRD = 1 upper surface • Initially locked in all DOFs VEHICLE • Gravity load to master node BOUNDARY CONDITIONS • Initial velocity to master node • Initial distance from free surface9/17
  12. 12. Numerical - Experimental Correlation All loadcases computed from 0 to 200 ms FOURTH SECOND THIRD FIRST • Impact angle 51 deg 19 35 deg • Flaps position 21deg 0 deg LOADCASE • Vertical velocity 3,4 m/s10/17
  13. 13. First Loadcase 0.2 AX - COG 0.1 0 -0.1 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 -0.2 -0.3 -0.4 -0.5 t [s] 0.6 AZ - COG 0.4 0.2 0 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 -0.2 t [s] Numerical Experimental11/17 All curves normalized to 1
  14. 14. Second Loadcase 0.1 AX - COG 0 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 -0.1 -0.2 -0.3 -0.4 t [s] 0.8 AZ - COG 0.6 0.4 0.2 0 -0.2 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 -0.4 t [s] Numerical Experimental12/17 All curves normalized to 1
  15. 15. Third Loadcase 0.3 AX - COG 0.2 0.1 0 -0.1 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 -0.2 -0.3 -0.4 t [s] 0.4 AZ - COG 0.3 0.2 0.1 0 -0.1 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 -0.2 t [s] Numerical Experimental13/17 All curves normalized to 1
  16. 16. Third Loadcase 19 deg Sensor 0.40 0.30 0.20 0.10 0.00 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 -0.10 t [s] Numerical Experimental 35 deg Sensor 0.80 0.60 0.40 0.20 0.00 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 -0.20 t [s] Numerical Experimental 1.00 51 deg Sensor 0.80 0.60 0.40 0.20 0.00 -0.20 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 t [s]14/17
  17. 17. Correlation results summary model updating activity • improvement of modelling Correlation approaches process • correction of individual parameters Main outcomes from acceleration results • very good correlation at COG in X and Z directions • satisfactory correlation at NOSE and REAR parts Main outcomes from pressure results • good correlation • impact event chronology • pressure time history signature • satisfactory correlation • pressure peak values15/17
  18. 18. Remarks and further developments Experimental numerical results deviation Flexible body Statistic data Exposed impact areas and behaviour dispersion mathematical model Alternative modeling methodology Structure Deformable body Fluid LAW51 Multimaterial with SPH method outlet treatment16/17
  19. 19. Thanks for your attention17/17

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