Research On The Thermal-control Method For Aircraft Wings And Thermal Performance Analysis Of The Heat Pipe

The leading edges of wings of supersonic aircraft will encounter severe aerodynamic heating during high-speed flight, and therefore how to effectively reduce the difference in temperature between the wings and the surrounding environment has become one of the key problems in enhancing the ability of infrared stealth of an aircraft. Heat pipe technology is a mature technology in the application of thermal protection for an aircraft, both at home and abroad. However, relevant researches and applications are mostly concentrated on satellites, space stations and other spacecrafts. For the technical security and some other reasons, there are few publications about the application of heat pipe technology on thermal control on wings of supersonic airplane, and there is no comprehensive program as well. And for the varieties of the heat pipe grooves types and the experimental environment, different conclusions were drawn from specific experimental researches on the heat pipe with axial grooves. In order to solve the problems put forward above, researches were conducted in this paper as follows:1. The aerodynamic heating status of an XX type fighter in a certain flight state is taken as an example to design a thermal-control program for its wings. The endothermic system and heat pipe system were considered in the program, including the selection of phase-changing material and packaging material in former system, the design of heat pipe in latter one, and the mass calculation and optimization of each other.2. Based on the design of the heat pipe system in thermal-control, an experimental bench for thermal performance of heat pipe was established. Further, the influence of heating power, working rake angle , cooling condition on axial temperature distribution on the heat pipe, the heat-transferring coefficients he of evaporation segment as well as hc of condensation segment, the thermal resistance R, and the equivalent thermal conductivity coefficients Keff are inspected. Relevant conclusions were educed as follows: Rake angle has an distinct effect on thermal performance of heat pipe; when under gravity, the thermal performance improves obviously comparing with the status of putting horizontally or reversely, but when working angle is above 30 the effect is not obvious; when heating power does not exceed the transfer limit of the heat pipe, the heat transfer characteristics of heat pipe could be improved by improving the condensing condition.These results are definite valuable in the application of heat pipe technology in thermal control of wings of supersonic aircrafts.