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A body flap/RCS-integrated configuration is often used to achieve pitch trimming and controlled flight in near space for hypersonic vehicles. Under the high temperature and pressure load induced by the expansion wave at the nozzle exit, the body flap is prone to significant structural deformation, which leads to a change in the resulting moment, even comparable to the control ability, and bring additional challenges to the control system. Based on the CFD/CTD/CSD coupling method, the aerothermoelastic effect on the aerodynamic characteristics and structural deformation of the body flap under jet interaction is systematically studied. Numerical results indicate that the pitching moment coefficients show an increasing trend for all the models, rigid, elastic and thermoelastic, while the increment significantly decreases with the increase in trajectory altitudes. With the increase in deflection angle, the pitching moment coefficients of the three models decrease nonlinearly at high altitude, and the aerothermoelastic effect significantly decreases. At a middle-lower altitudes, the pitching moment coefficient is reversed at a lager deflection angle, and the trailing edge of the body flap presents the deformation characteristics of upward bending, which makes the aerothermoelastic phenomenon degenerate into an aeroelastic problem. From the station along the chord and spanwise direction, the change in displacement increment of the thermoelastic model reflects the competitive relationship between normal stress and thermal stress imposed by jet interaction. [ABSTRACT FROM AUTHOR]

Our research aim is to investigate the buffet alleviation effect of static or vibrating bulges attached on the forebody surface of the model. Experiments and numerical simulations on a model consisting of a sharp-edged, 70°-leading edge sweep delta wing and twin swept back vertical tails were conducted. Models with different bulges were tested and computed at 10 and 20 m/s of free stream velocity at angles of attack ranging from 20°-50°. Dynamic strain gauge and multichannel data acquisition and analysis system were employed for the measurement of unsteady root strain on the vertical tails. Experimental and computational results show that both static and vibrating bulges behave effectively as a novel tool to alleviate tail buffet, and the alleviation effect depends largely on the vibrating frequency. Besides, one-sided bulge can only alleviate the buffeting response for the tail of the same side, and it has no obvious alleviation effect for the opposite tail. Results of the spectral analysis reveal that there are generally three peaks of spectral density for aircrafts of this configuration, and bulges used in this paper could alleviate tail buffeting, but the total lift and drag of the whole model show no obvious deviation compared to the base model and the dominant frequency of the vibration of the tails has not shifted. [ABSTRACT FROM AUTHOR]