tailieunhanh - Wind Tunnels and Experimental Fluid Dynamics Research Part 19

Tham khảo tài liệu 'wind tunnels and experimental fluid dynamics research part 19', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 708 Wind Tunnels and Experimental Fluid Dynamics Research Fig. 26. Temperature evolution for different time istants a point P1 b point P2 Fig. 27. Time evolution of temperature on the panel comparison between numerical and experimental results is quite good for the first phase of the test both during the initial heating from t 0 s to t 200 s and the following phase up to the steady state from t 200 s to t 570 s . On the other side after the backward movement the comparison shows some discrepancies. In this case in addition to the error associated to the numerical simulation there is also the increased uncertainty associated to the experimental measurement induced by a non optimized angle of view between the thermocamera and the model since this factor was optimized for the first position of the model. The behaviour of the curve is represented quite well by the numerical results being differences found in the absolute value of temperature of about 50K. The same consideration apply also for the analysis of the cooling phase. 709 Design Execution and Rebuilding of a Plasma Wind Tunnel Test Compared with an Advanced Infrared Measurement Technique 9. Conclusions The experimental and numerical activities carried out for the analysis of the PWT test on the wing leading edge model have been presented. The IR thermo-graphic images have been processed through an ad-hoc developed mapping procedure to be directly compared with the results of the numerical analysis carried out through a non standard approach based on the unsteady simulation of the test and a coupling between the external aerodynamic field and the internal thermal field. Differences of about 100K have been found between the experimental and numerical results at the end of the test. It has been found that these differences increased during the second phase of the test when the angle of view between the thermocamera and the panel was not optimized. It has to be remarked that some uncertainties can be also .