Hypersonic Aeroelastic and Aerothermoelastic Studies Using Computational Fluid Dynamics

Abstract

A framework for aerothermoelastic-stability-boundary calculation for hypersonic configurations using computational fluid dynamics combined with radial basis functions for mesh deformation is developed. Application of computational fluid dynamics enables one to consider different turbulence conditions, laminar or turbulent, and different models of the air mixture, in particular real-gas model, which accounts for dissociation of molecules at high temperature. The effect of transition on the flutter margin of the heated structure is also considered using an uncertainty-propagation framework. The aerothermoelastic-stability margin of a three-dimensional low-aspect-ratio wing, representative of a control surface of a hypersonic vehicle, is investigated for various flight conditions. The system is found to be sensitive to turbulence modeling, as well as the location of the transition from laminar to turbulent flow. Real-gas effects play a minor role for the flight conditions considered. This study demonstrates the advantages of accounting for uncertainty at an early stage of the analysis, and emphasizes the important relation between transition from laminar to turbulent, thermal stresses, and stability margins of hypersonic vehicles.

Generalized Formulation and Review of Piston Theory for Airfoils

“…(15). Noting the relationship between derivatives of the two planes, the Euler equations as written in the z-x plane Eqs.…”

“…However, piston theory enjoyed renewed attention in the 1990s, with the early implementation of piston theory with Euler solutions in CFD [8] and with continued development of aeroelastic panel codes [9]. The 2000s saw a marked resurgence in the interest in piston theory as a computationally inexpensive method for modelling supersonic and hypersonic aeroelastic problems, with applications being found in aeroservo-elasticity and aero-thermo-elasticity, with the further integration of piston theory with CFD; recent literature highlights the continued application of piston theory in reducing the computational cost of CFD for hypersonic aeroelasticity [10][11][12][13][14][15].…”

Transient Temperature Effects on the Aerothermoelastic Response of a Simple Wing

“…Whereas the early research was instrumental in providing the basis for the aerothermoelastic design of the X-15 and the space shuttle [3][4][5], the current focus is on the development of hypersonic technologies for next-generation reusable launch vehicles and hypersonic cruise vehicles [6][7][8]. Current research includes: development of reduced order models for aerothermoelastic systems [9,10], structural optimisation [11], uncertainty propagation [12,13], coupling CFD with aerothermoelastic models [14], two-dimensional nonlinear flutter models [15] and three-dimensional flutter models [16]. This work has shown that the dynamic behaviour of the structure under the harsh thermal environment must be investigated for hypersonic aircraft to become a reality.…”

Application of the Deconvolution Methods for Processing of Measurement Signals in the Fast Processes

“…At hypersonic speeds, aerodynamic heating leads to extremely high heat flow and temperature on the outer surface of the machine and in the channel of the hypersonic propulsion air-jet engine [1]. A well-designed thermal protection system must maintain the integrity of the aircraft, preventing the thermal loads.…”

“…Security, viability and stability are key considerations in achieving the goals of the flight. For their achievement, the knowledge of temperatures and heat flows for creation of effective thermal protection system [1,2] is required.…”