NUMERICAL MODELING AND DYNAMIC SIMULATIONS OF NONLINEAR AEROTHERMOELASTIC OF A DOUBLE-WEDGE LIFTING SURFACE

The design of the re-entry space vehicles and high-speed aircrafts requires specialattention to the nonlinear thermoelastic and aerodynamic instabilities of theirstructural components. The thermal effects are important since temperatureenvironment influences significantly the static and dynamic behaviors of flightstructures in supersonic/hypersonic regimes. To contribute to the understanding ofdynamic behavior of these “hot” structures, a double-wedge lifting surface withcombined freeplay and cubic stiffening structural nonlinearities in both plungingand pitching degrees-of-freedom operating in supersonic/hypersonic flight speedregimes has been analyzed. A third order Piston Theory Aerodynamics is used toevaluate the applied nonlinear unsteady aerodynamic loads. The loss of torsionalstiffness that may be incurred by lifting surfaces subjected to axial stressesinduced by aerodynamic heating is also considered. The aerodynamic heatingeffect is estimated based on the adiabatic wall temperature due to high speedairstreams. Modelling issues as well as simulation results have been presented andpertinent conclusions outlined. It is highlighted that a serious loss of torsionalstiffness may induce the dynamic instability of the lifting surfaces. The influenceof various parameters such as flight condition, thickness ratio, freeplays andpitching stiffness nonlinearity are also discussed.