Optimization of Airship Envelope Shape using Computational Fluid Dynamics
Tushar Sham Kanikdale,
M.Tech,
04,
75 pp.
Department of
Aerospace Engineering
Indian Institute of Technology Bombay,
Powai, Mumbai 400 076.
Supervisor(s):
A. G. Marathe, R. K. Pant
This work aims to arrive at the optimum shape of an airship envelope of fixed volume from aerodynamic and structural
considerations, using the concept of multi-disciplinary design optimization. The multi-disciplinary nature of the problem
is discussed and the corresponding objective functions and the constraints are elucidated. The strategies adopted are
described along with the shape generation algorithm. Fluent CFD code has been used for computational experimentation in
conjunction with SIMANN, simulated annealing code for optimization. The low fidelity model available in the literature
was found to give large deviations from the physical value of envelope drag. The mathematical model for envelope
drag estimation has been developed based on the detail study of results obtained through CFD experimentation. It was
observed that the shape optimized for minimum drag shows a significant improvement over a reference GNVR shape.
The multi-disciplinary nature of the problem is addressed by devising a composite objective function
and corresponding results are presented.
Keywords: airship envelope shape, optimization, CFD, simulated annealing, mathematical models