Ablation Analyses of Optimized Nose Tips for Hypersonic Vehicles

Onay, Oguz K.
Eyi, Sinan
An accurate and efficient design optimization method is developed for hypersonic vehicles. For flow analysis, the axisymmetric Navier-Stokes and finite-rate chemical reaction equations are solved implicitly using Newton's method. A gradient-based method is implemented for numerical optimization. Sensitivities are evaluated using the discrete adjoint method. Bezier curves are used for geometry parameterization. The objective of design is to minimize drag while keeping aerodynamic heating below initial values. Although the ablation analysis is excluded in the design process, the noncharring ablation characteristics of the baseline and optimized geometries are compared. An implicit method is developed for the analysis of carbon ablation. The surface thermochemistry and axisymmetric heat conduction equations are solved simultaneously. A thermochemical equilibrium assumption is employed at the surface. Results are demonstrated for a simple sphere-cone geometry.


Aerothermodynamic Design Optimization of Hypersonic Vehicles
Eyi, Sinan; Boyd, Iain D. (American Institute of Aeronautics and Astronautics (AIAA), 2019-04-01)
The objective of this study is to develop a reliable and efficient design optimization method for hypersonic vehicles focused on aerothermodynamic environments. Considering the nature of hypersonic flight, a high-fidelity aerothermodynamic analysis code is used for the simulation of weakly ionized hypersonic flows in thermochemical nonequilibrium. A gradient-based method is implemented for optimization. Bezier or nonuniform rational basis spline curves are used to parametrize the geometry or the geometry ch...
Trajectory optimization of advanced launch system
Karsli, G; Tekinalp, Ozan (2005-06-11)
Trajectory optimization of an advanced launch vehicle is addressed. The optimal control problem is converted into a parameter optimization problem. Then, simulated annealing based single and multiobjective optimization algorithms are used. The single objective optimization problem is formulated to minimize the total flight time, while the multiobjective formulation tries to maximize payload mass and orbit insertion velocity. The problem is also solved using our novel multiple cooling multiobjective simulate...
Multiobjective design optimization of rockets and missiles
Öztürk, Mustafa Yavuz; Tekinalp, Ozan; Department of Aerospace Engineering (2009)
Multidisciplinary design optimization of aerospace vehicles has attracted interest of many researchers. Well known aerospace companies are developing tools for the mutlidisciplinary design optimization. However, the multiobjective optimization of the design is a new and important area investigated very little by the researchers. This thesis will examine the approaches to the multiobjective and mutlidisciplinary design optimization of rockets and missiles. In the study, multiobjective optimization method cal...
Error analysis and assessment of unsteady forces acting on a flapping wing micro air vehicle: free flight versus wind-tunnel experimental methods
Caetano, J. V.; Perçin, Mustafa; van Oudheusden, B. W.; Remes, B.; de Wagter, C.; de Croon, G. C. H. E.; de Visser, C. C. (IOP Publishing, 2015-10-01)
An accurate knowledge of the unsteady aerodynamic forces acting on a bio-inspired, flapping-wing micro air vehicle (FWMAV) is crucial in the design development and optimization cycle. Two different types of experimental approaches are often used: determination of forces from position data obtained from external optical tracking during free flight, or direct measurements of forces by attaching the FWMAV to a force transducer in a wind-tunnel. This study compares the quality of the forces obtained from both m...
Design optimization of variable frequency driven three-phase induction motors
Ertan, B; Leblebicioğlu, Mehmet Kemal; Simsir, B; Hamarat, S; Cekic, A; Pirgaip, M (1998-01-01)
An approach to optimize the design of three-phase induction motors for a wide speed range drive is considered. Two operating points in the speed range are taken into consideration. The problem is handled as a constrained optimization problem. An accurate model for the motor in terms of its dimensions has been developed which predicts the motor performance based on about 60 parameters of motor geometry.
Citation Formats
O. K. Onay and S. Eyi, “Ablation Analyses of Optimized Nose Tips for Hypersonic Vehicles,” JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER, pp. 78–89, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/33302.