Design And Simulation Of Graphite Heater For Hupersonic Vehicle Thermal Test

With the development of aerospace technology,hypersonic aircraft such as aerospace aircraft,hypersonic fighter aircraft,hypersonic missiles and space return vehicles are increasingly used.These hypersonic vehicles will face harder aerodynamic heating than traditional supersonic vehicles.It is necessary to set higher temperature thermal environment tests on the ground during the researching these aircraft.As aircraft speed higher,the thermal test equipment of aircraft ground structure is also upgrading and increasing the temperature.The heating equipment for ground thermal test has gradually changed from quartz lamp heater to graphite heater.The research on the application of graphite heater in the thermal test of aircraft ground structure in China has not been fully developed.This paper mainly designs a graphite heater for the hypersonic aircraft nose cone.Through finite element analysis software verified the radiant heating and water cooling of this heater.The main research contents and conclusions are as follows:(1)Use Creo to innovatively design and model a spherical graphite heater based on the radiation characteristics of graphite materials.Spheric graphite heater aims at the nose cone of hypersonic vehicle,it fills the vacancy of domestic spherical graphite heater.The heater can heat the specimen within a diameter of 800 mm.The heater can replace the different graphite elements to change the maximum input power to adapt different heating tests.(2)Use ANSYS to simulate the radiation heat transfer of the spherical graphite heater.Researched the strips temperature distribution and radiative heat flux of graphite heater,and researched the temperature distribution of tested pieces.The heater can heat the tested pieces to more than 2000°C,and the heat flux in the central area is above 1.5MW/m~2.The spherical heater structure has obvious effect on the concentration of heat flux.In the process of simulation research,I established the scheme and process of graphite heater simulation.(3)Fluent is used to simulate the water-cooled reflector and water-cooled electrode of the heater to analyze the heat exchange capability.The reflector and the electrodes designed in this paper made the temperature of the back of the heater about 80°C in high temperature environment,which adapted the heat transfer demand of the heater.(4)A unit experimental device is designed and built to verify the heating capacity of the spherical heater.The temperature of graphite strips was monitored by thermal imager,and the heat flux density was monitored by heat flow meter.When the current reaches 813A,the maximum temperature reaches1869.2°C and the heat flux reaches 592.9 k W/m~2.The article established a model with the same experimental conditions,and compared it to simulation.It was found that the digital simulation model of the graphite heater was quite consistent with the actual test results.