Document Type : Original Article

Authors

1 Faculty of Aerospace engineering Amirkabir University

2 Aerospace Research Institute

3 Iranian Space Research Center

Abstract

Airships usually have low cruising speed due to their large volume and high drag level. This makes the aerodynamic design of the vehicle, including the surfaces shape, the length-to-diameter ratio and the position of the fins, all very important. Furthermore, an important parameter in the vehicle aerodynamic drag is determining the flow separation area at the rear of the air vehicle. The flow separation plays an essential role in the amount of drag and lift force, so the location of the fins and the design of the rear of the airship will be very important. By using both analytical and numerical methods, this study examines the aerodynamic efficiency of an airship in three different configurations, focusing on the location, type, and angle of attack of the fin, and compares analytical and numerical results. According to studies conducted among the types of fins, the cross-type will have the best performance among the fins in terms of lift-drag ratio. Also, moving the fins forward and distancing them from the rear of the vehicle disrupts the flow pattern at the rear of the vehicle and delays separation. This will improve aerodynamic efficiency and improve the lift-drag ratio of the vehicle.

Keywords

Main Subjects

Article Title [فارسی]

Investigation of fin changes effects on aerodynamic performance of airship

Authors [فارسی]

  • Sahar Noori 1
  • Mohamad Saleh Afshar 2
  • Nima Karimi 3

1 Faculty of Aerospace engineering Amirkabir University

2 Aerospace Research Institute

3 Iranian Space Research Center

Abstract [فارسی]

Airships usually have low cruising speed due to their large volume and high drag level. This makes the aerodynamic design of the vehicle, including the surfaces shape, the length-to-diameter ratio and the position of the fins, all very important. Furthermore, an important parameter in the vehicle aerodynamic drag is determining the flow separation area at the rear of the air vehicle. The flow separation plays an essential role in the amount of drag and lift force, so the location of the fins and the design of the rear of the airship will be very important. By using both analytical and numerical methods, this study examines the aerodynamic efficiency of an airship in three different configurations, focusing on the location, type, and angle of attack of the fin, and compares analytical and numerical results. According to studies conducted among the types of fins, the cross-type will have the best performance among the fins in terms of lift-drag ratio. Also, moving the fins forward and distancing them from the rear of the vehicle disrupts the flow pattern at the rear of the vehicle and delays separation. This will improve aerodynamic efficiency and improve the lift-drag ratio of the vehicle.

Keywords [فارسی]

  • Airship
  • Aerodynamic
  • Aerodynamic configuration
1- Carrion, M, Steijl, R., Barakos, G., and Stewart, D. (2016) Analysis of hybrid air vehicles using computational fluid dynamics. Journal of Aircraft, 53(4), pp. 1001-1012.
2- Technical manual of airship aerodynamics, war department, February 1941. TM1-320.
3- K. E. Omari, E. Schall, B. Koobus, A. Dervieux, TURBULENCE MODELING CHALLENGES IN AIRSHIP CFD STUDIES, 2004.
4- K.Shields, CFD APPLICATIONS IN AIRSHIP DESIGN, Thesis submitted to the College of Engineering and Mineral Resources at West Virginia University, 2010.
5- V. Voloshin, Y.K. Chen, R. Calay, A comparison of turbulence models in airship steady-state CFD simulations, October 11, 2012.
6- A. D. Andan, W. Asrar, A. A. Omar, Investigation of Aerodynamic Parameters of a Hybrid Airship, Journal of Aircraft, 2012.
7- L.Ping, G.yi Fu, L.j.Zhu, X.l.Wang, Aerodynamic characteristics of airship Zhiyuan-1, Journal of Shanghai Jiaotong University (Science) 18(6):679- 687, DOI:10.1007/s12204-013-1443-9, December 2013.
8- C.Yanxiang, Y.Yanchu, Zh.Jianghua, Zh. Xiangqiang, Y.feng, Numerical Aerodynamic Investigations on Stratospheric Airships of Different Tail Configurations, Conference Paper · March 2015.
9- Jefferson L. Mendonça Junior, Jonatas S. Santos, Maurício A. Morales, Luiz C. Goes, Stojan Stevanovic and Rodrigo A. Santana, Airship Aerodynamic Coefficients Estimation Based on Computational Method for Preliminary Design, AIAA 2019-2982.
10- D. Monk, E.A. Chadwick, Comparison of Turbulence Models Effectiveness for a Delta Wing at Low Reynolds Numbers, european conference for aeronautics and space sciences, 2017.
11- THE USAF STABILITY AND CONTROL DATCOM, Volume I, Users Manual, From AFFDL-TR-79-3032, 1999.
12- Carrion, M., Steijl, R., Barakos, G., and Stewart, D. (2016) Analysis of hybrid air vehicles using computational fluid dynamics. Journal of Aircraft, 53(4), pp. 1001- 1012.