Research On Miniaturized Temperature Measuring Device For Thermo-structural Materials Of Hypersonic Vehicles

The in-flight measurements of parameters like temperature, and heat flux areof great significance for thermal protection system estimate and design. Newgeneration hypersonic vehicles will have a long time flight in the atmosphere;with subsequently have an extremely serious heat accumulation effect, whichcauses thermal protection materials’ temperature is extremely high. Traditionalcontact measurements which based on thermocouples cannot meet therequirements of the durable parameters identification of temperature and heatflux in that region. Noncontact temperature measurement based on radiationmeasuring has advantages such as wide temperature measurement range and ashort response time. A miniaturized temperature measurement device based onnon-contact temperature measurement is designed; surface heat fluxidentification was completed using the thermal structure rear side temperature-time history. This article provides an important method for hot structure materialassessment in hypersonic flight test.(1)The methods of non-contact temperature measurement based on radiationwere researched, and ways of monochro me and two-color methods of surfacetemperature measurement determined by material thermal radiation wererespectively studied. Additionally, the thermal protection layer outside heat fluxidentification methods, illiterate that two-color methods is more suitable for hotstructure material temperature testing of high temperature area;(2)Lumped parameter method and method of considering one-dimensionalheat conduction were respectively used for numerical calculate method of surfaceheat flux based on the thermo-structural material rear side temperature data, andthe algorithm’s scope of application and accuracy was discussed;(3)A miniaturized temperature measurement device designed. Optical path design was made to meet the requirement of radiation signal obtain, by which thestructure ins ide shape was determined. Reliability analysis proved that relativeerror caused by Optical system design is less than0.3%testing temperaturewithin the designed measurement range; structure material system, devicestructure shape structure were determined considering its high temperaturestrength and heat insulation performance, and the structural strength, heat sealingefficiency analyzed using finite element method.(4)The miniaturization temperature measurement device sample wasprepared, which lighter than1.5kg. The ground assessment experiment wasdesigned for temperature measurement device structure strength and heatinsulation and sealing performance assessment test. The sample did not damaged,and flange temperature always lower than70℃, proved that designed devicehave enough strength and good high heat sealing performance.(5)One-dimension heat conduction experiment samples were prepared, andusing the solar energy magnification device as the heat source, the rear sidetemperature of heat structural materials was measured, calculated heat flux usingheat flux identification method result to be0.64MW/m~2,0.35MW/m~2and0.28MW/m~2respectively in three experiments.