Experiment Design Method For Large Gradient Thermal Environment Employing Quartz Lamp Array

As an important radiating heat source in static thermal test,quartz lamp array is widely used in aircraft structural thermal test due to its advantages of low cost and strong adaptability.Due to the complex heat flow distribution on the surface of aircraft structure,there is a large gradient thermal environment,while the traditional quartz lamp array layout design is difficult to meet the simulation requirements.This paper provides a design method for the simulation of large gradient thermal environment based on the quartz lamp array through the optimization design research.Firstly,based on the theory of analytic method and monte carlo method(MCM)simulation of the quartz lamp array radiation heat flux distribution difference is small,the monte carlo method is adopted to establish THE quartz lamp array radiation heat flow field distribution model and design verification test,THE test surface heat flux distribution of the simulation calculation results compared with the test results,found that small difference in.It shows that the model of radiant heat flow field of quartz lamp array is correct.Secondly,according to the test requirements of quartz lamp array heating with limited power and large heat flow,the influence of the lamp tube and its arrangement on the heating uniformity was analyzed.The mean value of heat flow on the tested surface was 120k W/m~2,and the quotient of the standard deviation and the mean value of heat flow on the tested surface was used to represent the uniformity.In order to improve the feasibility of optimization,the sensitivity of parameters affecting the heat flux distribution on the tested surface in the model was compared.The optimization parameters of the model were determined as the horizontal spacing and height difference between adjacent lamps of the quartz lamp array,and the minimum horizontal spacing of adjacent lamps was determined to be17mm through the simulation results.When the quartz lamp array is designed according to the elliptic function arrangement,the heat flux uniformity of the tested surface is 70.50%,which is 24.89%higher than that of the initial quartz lamp array with equal spacing.In order to further improve the applicability of the model,the thermal power parameters of the model were retrieved from the test results,and the conversion relationship of the electrothermal power characteristics of the quartz lamp array was obtained.Finally,the large gradient heat flow distribution around the stagnation point on the radome surface was taken as the background and transformed into a planar large gradient thermal environment.The thermal environment on the left and right sides of the gradient heat flow distribution was subdivided into single gradient and complex gradient thermal environment according to the difference of the thermal environment on the left and right sides of the gradient heat flow distribution.Based on the test surface heat flux distribution is homogeneous,using partition optimization integration strategy,the large gradient thermal environment can be divided into heat flux changes mutation area and smooth area,use a small amount of light tube heat flux distribution simulated mutation area,and the dense take,to test all point mutations in the area and the surface heat flow density difference and minimum variance optimization model.In the stationary area,the uniform optimization method of heat flux distribution on the test surface was adopted to simulate the overall large gradient thermal environment,and the quartz lamp array layout design was improved.It is found that the heat flow distribution on the tested surface after optimization is very consistent with the corresponding large gradient thermal environment,indicating that the optimization of the quartz lamp array radiation heat flow field distribution model can well solve the problem that the large gradient thermal environment is difficult to simulate.