| In the ablative thermal protection system, the ablation rate is an importantindex to evaluate the thermal protection materials and thermal protection system.The ablation of materials directly affects the reliability aircraft aerodynamicshape and structure. Accurate characterization method of ablation rate is veryimportant to both the design of thermal structure and reliability evaluation.Methods by measuring changes in static thickness for the ablation rate averagecannot meet the application requirements in terms of accuracy and real-timeperformance. The method of laser feed limited to the stability of the rack andfeeding accuracy, precision and real-time performance is difficult to achieve.This paper designs and examine of a test method of dynamic ablation rate basedon CCD image sensor. Compared with traditional method,it has significantimprovement in accuracy and real-time. This paper provides important referencefor the design and evaluation of hypersonic vehicle thermal protection structure.(1) Methods using laser marking and filter selectivity filter collection pointat high temperature and high brightness environment, calculating the spacecoordinate by the method of digital image processing. It achieves dynamicablation rate measurement.(2) Testing of graphite, carbon-carbon, refrasil and carbon phenolic materialusing the method proposed in this paper. Adopt different heating ways underdifferent heat output on the test-piece carried out ablation test for its ablation rate.Ablation measurement resolution can reach0.1mm, the ablation rate testingprecision of0.01mm/s. The experimental values and the static measurementdifference less than2%(3) Calculate Arrhenius activation energy by measuring the static ablationamount. Derived for ablation rate according to Arrhenius formula, determine thenecessary environmental parameters. Obtained relationship between theArrhenius linear ablation rate and temperature. Comparison of Arrhenius linearablation rate and the measured value curve. |
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