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Effects of targeting pod modification on F/A-18C Hornet weapons release

Published online by Cambridge University Press:  27 January 2016

C. W. O’Brien
Affiliation:
Department of Mechanical Engineering, United States Naval Academy (USNA), Annapolis, USA
M. R. Snyder
Affiliation:
Department of Mechanical Engineering, United States Naval Academy (USNA), Annapolis, USA
E. N. Hallberg
Affiliation:
Department of Aerospace Engineering, USNA, Annapolis, USA
A. Cenko
Affiliation:
Store Separation Consultant, Dunkirk, Maryland, USA

Abstract

This paper describes a study that investigated the efficacy of modifications to the trailing end of the externally mounted advanced targeting forward looking infrared pod (ATFLIR) on the store separation characteristics of the F/A-18C aircraft. Prior work by Godiksen suggests that the trailing end of the geometrically similar targeting forward looking infrared pod (TFLIR) is the likely source of shock waves that can adversely impact the trajectory of a recently released store. In our study five different modifications to the aft end of the ATFLIR were analysed using computational fluid dynamics (CFD). The two most promising designs, an ogive shape such as that used in artillery shells and rockets, and a simpler extended but truncated cone shape were then further investigated. The moments that these trailing shapes produced on an adjacent released store were compared. CFD analysis revealed that the simpler cone shape resulted in weaker shocks from the aft end of the pod with a resultant smaller adverse moment on the store. While there is an extensive history of using CFD to predict store separation behavior, results from our study should be compared with wind tunnel data in order to validate the CFD simulations.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2012 

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References

1. Godiksen, W. Effects of targeting pods addition on F/A-18C Hornet weapons release, 2008, AIAA 2008-6380: Atmospheric Flight Mechanics Conference and Exhibition, 2008, Honolulu, Hawaii, USA.Google Scholar
2. Rogers, R. A comparison between the Nielson and Woodward programs in predicting flow fields and stores loads, 1976, Naval Weapons Center TM2854.Google Scholar
3. Cenko, A. and Tinoco, E., PAN AIR – weapons, carriage and separation, 1979, Air Force Flight Dynamics Laboratory TR-79-3142.Google Scholar
4. Steger, J., Dougherty, F. and Benek, J. A Chimera grid scheme, Advances in grid generation, 1983, American Society of Mechanical Engineers Fluids Engineering Conference, 1983, Houston, Texas, USA.Google Scholar
5. Cenko, A. Store separation lessons learned during the last 30 years, 2010, ICAS 2010-2.11ST1, 27th International Congress of the Aeronautical Sciences (ICAS), 2010, Nice, France.Google Scholar
6. Keen, K. Inexpensive calibrations for the influence function method using the interference distributed loads code, J Aircr, January 1985, 22, (1), pp 8587.Google Scholar
7. Cenko, A., Meyer, R. and Tessitore, F. Further development of the Influence Function Method for store aerodynamic analysis, J Aircr, August 1986, 23, (8), pp 656661.Google Scholar
8. Cenko, A. and Lutton, M. ACFD application to store separation – status report, Aeronaut J, October 2000, 104, pp 459466.Google Scholar
9. Walsh, J. and Cenko, A. USM3D Prediction of Mk-83 trajectories from the CF-18 Aircraft, 2001, AIAA 2002-2431, 19th Applied Aerodynamics Conference, 2001, Anaheim, CA, USA.Google Scholar
10. Ryckerbusch, C., Niewoehner, R., Cenko, A., Sisco, B. and Walsh, J. Evaluation of the capabilities of CFD to predict store trajectories from attack aircraft, 2002, AIAA 2002-0279, 40th Aerospace Sciences Meeting, 2002, Reno, NV, USA.Google Scholar
11. Cenko, A., Niewoehner, R. and Ryckebusch, C. Evaluation of the capabilities of CFD to predict store trajectories from attack aircraft, 2002, ICAS 2002-2.6.1, 23nd International Congress of Aeronautical Sciences, 2002, Toronto, Canada.Google Scholar
12. Frink, N. Upwind scheme for solving the Euler equations on unstructured tetrahedral meshes, AIAA J, January 1992, 30, (1), pp 7077.Google Scholar
13. Frink, N. Recent progress toward a three-dimensional unstructured Navier-Stokes flow solver, 1994, AIAA 1994-0061, 32nd Aerospace Sciences Meeting and Exhibition, 1994, Reno, NV, USA.Google Scholar
14. Frink, N. Tetrahedral unstructured Navier-Stokes method for turbulent flows, AIAA J, November 1998, 36, (11), pp 19751982.Google Scholar
15. Frink, N., Pirzadeh, S., Parikh, P., Pandya, M. and Bhat, M. The NASA Tetrahedral Unstructured Software Systems (TetrUSS), 2000, ICAS 2000-2.4.1(IL), 22nd International Congress of Aeronautical Sciences, 2000, Harrogate, UK.Google Scholar
16. Welterlen, T. and Leone, C. Application of viscous, Cartesian CFD to aircraft store carriage and separation simulation, 1996, AIAA 1996-2453, 14th Applied Aerodynamics Conference, 1996, Denver, CO, USA.Google Scholar
17. Welterlen, T. Store release simulation on the F/A-18C using split flow, 1999, AIAA 99-0124, 37th Aerospace Sciences Meeting and Exhibition, 1999, Reno, NV, USA.Google Scholar
18. Cenko, A.T., Cenko, A.T., Piranian, A. and Denihan, S. Utilizing flight test telemetry data to improve store trajectory simulations, 2003 AIAA 2003-4225, 21st Applied Aerodynamics Conference, 2003, Orlando, FL, USA.Google Scholar
19. Ray, E. CFD method for separation of SLAM-ER from S-3B, 2003, AIAA 2003-4226, 21st Applied Aerodynamics Conference, 2003, Orlando, FL, USA.Google Scholar
20. Jespersen, D., Pulliam, T. and Buning, P. Recent enhancements to OVERFLOW, 1997, AIAA 1997-0644, 35th Aerospace Sciences Meeting and Exhibition, 1997, Reno, NV, USA.Google Scholar
21. Spalart, P. and Allmaras, S. A one-equation turbulence model for aerodynamic flows, 1992, AIAA 1992-0439, 30th Aerospace Sciences Meeting and Exhibition, 1992, Reno, NV, USA.Google Scholar
22. Cenko, A. One CFD calculation to end point flight testing (has CFD finally replace the wind tunnel?), Aeronaut J, July 2006, 110.Google Scholar
23. Cenko, A. Lessons Learned in 30 years of store separation testing, 2009, AIAA 2009-98, 47th Aerospace Sciences Meeting, 2009, Orlando, FL, USA.Google Scholar
24. Snyder, M., Shah, R., O’Brien, C., Davis, N., Metzger, J., Nordlund, R. and Smith, M. Strut effects on store freestream aerodynamics, 2011, AIAA 2011-3159, 29th Applied Aerodynamics Conference, 2011, Honolulu, HI, USA.Google Scholar
25. Godiksen, W. and Hallberg, E. Targeting pod effects on weapons release from the F/A-18C, 2008, ICAS 2008-2.9.4, 26th Congress of International Council of the Aeronautical Sciences, 2008, Anchorage, AK, USA.Google Scholar
26. Simpson, S., Snyder, M. and Cenko, A. Effects of the Litening and ATFLIR external targeting pods on F/A-18C Hornet weapons release, 2011, AIAA 2011-3157, 29th Applied Aerodynamics Meeting, 2011, Honolulu, HI, USA.Google Scholar
27. Veazey, D. and Hopf, J. Comparison of aerodynamic data obtained in the Arnold Engineering Development Center wind tunnels 4T and 16T, 1998, AIAA Paper 1998-2874, 20th Advanced Measurement and Ground Testing Technology Conference, 1998, Albuquerque, NM, USA.Google Scholar
28. Drobik, J. and Lam, S. Validation of plane of symmetry testing in the DSTO 0·8m wind tunnel, 2010, International Test and Evaluation Association, 15th Aircraft/Stores Compatibility Symposium, Fort Walden Beach, 2010, FL, USA.Google Scholar
29. Shea, M., Constantino, M., O’Brien, C., Snyder, M., Simpson, S. and Cenko, A. Litening Pod modification to improve Mk-83 trajectories, 2011, AIAA 2011-3158, Applied Aerodynamics Conference, 2011, Honolulu, HI, USA.Google Scholar