Investigation Of Pressure Uncertainty For Two-component Pressure Sensitive Paint

Pressure sensitive paint(PSP)test technology using the photoluminescence properties and oxygen quenching of the macromolecule organic measure the pressure of model surface,the technique can obtain high-resolution surface pressure map,makes up the weaknesses and the disadvantages of traditional pressure measurement techniques,received extensive concern and development in recent twenty years.At present,the domestic and international research mechanisms have studied deeply on experimental method and postprocessing technique of PSP,but seldom involves the research relating to error analysis and uncertainty of PSP system,especially for two-component PSP system.Through comprehensive use of theoretical analysis,mathematical derivation and experimental means,the uncertainty of two-component PSP system was systematically investigated in this paper.The dissertation's main work is as following:1?The valuation method for pressure uncertainty of two-component PSP system is established.The classical Stern-Volmer relation applicable for two-component PSP and the output signal expression of photodetector is deduced,the error sources of PSP technique are identified and generation mechanisms of error sources are analyzed.Based on the classical Stern-Volmer relation,the generalized Stern-Volmer relation as an basic physical formulas for deducing valuation method of two-component PSP system uncertainty is deduced by eliminating or separating error sources.Based on error transfer theory and generalized Stern-Volmer relation,the sensitivity coefficient and basic variance of error sources and the total uncertainty is derived,the valuation method for pressure uncertainty of two-component PSP system is established.2?The accuracy and applicability of the valuation method for two-component PSP system uncertainty is verified.Based on error simulating idea,coating photodegradation,surface pollution,light intensity changes of excitation source and images registration error are simulated by changing the pressure in calibration box and light power,spectra leakage is simulated using assumption method or replacing filter method,photo shot noise is simulated by dark current,reference pressure error and coating calibration error is simulated by assumption method,temperature error is simulated by changing the temperature in calibration box.A series of calibration tests are implemented,the test results expound the applicable condition of valuation method,verify the applicability of valuation method in engineering practice.3?Based on the derivation process of generalized Stern-Volmer relation,the error correction mechanism of the coating layer's thickness change,the distance variance between the measuring point and lens,the intensity change of excitation light and the coating's temperature effect for two-component PSP is elucidated.The relative calibration tests are implemented,the test results verify the correctness of the correction mechanism and an obvious correcting effect,prove the advantage of two-component PSP in engineering application.4?Based on the valuation method of two-component PSP system uncertainty,in the case of only considering photo shot noise,the expressions of pressure resolution limit and pressure coefficient resolution limit suitable for one dimensional isentropic flow and normal shock wave are deduced,the relationship between pressure resolution limit,pressure coefficient resolution limit and the calibration coefficient,surface pressure,the total pressure,Mach number is studied,some methods and criterion of improving experimental precision are proposed.5 ? Based on uncertainty propagation equation of two-component PSP and Lagrange multiplier solution,the expression of basic error allowable upper limit is deduced,16 terms error allowable limits is estimated,the relationship between basic error allowable limits and pressure,temperature,calibration coefficients,the temperature derivative of calibration coefficients is studied,the difference of basic error allowable upper limits between one-component PSP and two-component PSP is compared,the important error sources under different working conditions are pointed out,some methods improving experimental precision are proposed.6?Based on the valuation method of two-component PSP system uncertainty,the pressure uncertainty distributed on the upper surface of a certain type of airliner's wing is estimated,the distribution law of pressure uncertainty is studied,the reasons of the higher pressure uncertainty in wing leading edge and higher pressure gradient position is investigated,the major error sources of two-component PSP tests is identified,the influence degree,region and mechanism of coating calibration precision and image registration precision on pressure uncertainty is studied.7?According to coating calibration coefficients as important error sources in two-component PSP tests,a series of calibration tests are implemented,the influence degree of image intensity,the number of average images,image region,image filtering,image definition and the A/D conversion digit number on the coating calibration precision is studied.Finally,the implementing criteria and methods suitable to two-component PSP calibration tests is summarized.8?The interface software of the coating calibration and wind tunnel test for two-component PSP is developed.9?The full text is summarized,main creative points and the development direction of PSP uncertainty are pointed out.