Research On Correction Method And Application Of The Transient Thermal Model Of Spacraft

Thermal analysis is a key method for optimization of spacecraft's thermal control design, performance calibrat ion, prediction of temperature in orbit and diagnostics of thermal controlling accident. Its accuracy would directly determine the success of spacecraft engineering. The simplif ication and assumption of thermal analysis model would cause deviation between the model and the realistic. Thus using thermal experiment's date to correct thermal analysis model is a key part to spacecraft's thermal control system design and the correction method become key technology to thermal control system. At present, researches most focus on steady thermal analysis method. With the development of spacecraft transient thermal analysis and experiment, it is important to carry out correction method research to transient thermal analys is. For these above problems, this paper carried out research on:Firstly, by analyzing spacecraft steady thermal analysis model's random approximate correction method and transient thermal analysis model's characteristics, this paper acquire the key research part of transient thermal analysis model's correction method which using random approximate correction method. It primary consist of the building method of temperature deviation objection function adapt to transient thermal analysis model and opt im izat ion method of approaching object function. Besides the part of paper build the procedure of transient thermal analysis model's correction method basically.After that, based on the building transient m inimum deviation object-function, this paper researched effect on transient thermal analysis model of different approaching method of object function. The results show that when using BFGS method, deviation correction performance of part of heat transfer parameters is good and the deviation is under 10%. While deviat ion correction performance of some other part of heat transfer parameters is bad and the deviation is under 70%; When using genetic algorithm, most parameter's deviation is under 10% after correction and the maximum deviat ion is 48%. Combine the correction results and heat transfer parameter, this paper analys is the sensitivity of transient temperature. The results show that BFGS algorithm is adapt to heat transfer parameter with high sensitivity, while the genetic algor ithm is adapt to heat transfer parameter with low sensitivity. Combining the two algorithms can reach a good correction result.In addition, from the analysis of transient temperature deviation of above correction's results, its show that deviation of wave crest of transient temperature at some object point is big, up to 5?. Then deviat ion correction method with object function using transact wave crest trough as minimal and weight coefficient was built. This step would improve correct accuracy of heat transfer parameter. The deviat ion results with application of improved object function show that the maximal heat transfer parameter accuracy decrease from 70% which using above deviation method to 50%.At last, this paper built the transient thermal analysis model's layered correction system method. By using the transient temperature' minimum deviation as object function, the first layer would use BFGS algor ithm to correct heat transfer parameter with high sensitivity and then use genet ic algor ithm to correct heat transfer parameter with low sensitivity. The second layer would use BFGS algor ithm and genet ic algorithm separately to correct heat transfer parameter with object function using transact wave crest trough as minimal and weight coefficient. Utilize this system method to correct a micro satellite's thermal analysis model and the results show that the thermal analysis and experiment transient temperature deviat ion change from 8? to 2? which prove this system method's effectiveness.This paper's work meet the urgent need of effect correction method for transient thermal analysis model from nowadays' engineering and improve the system of key technology of spacecraft thermal controlling.