JAXA 2m×2m遷音速風洞（JTWT)における 抵抗推算精度の向上

摘要

In the JAXA 2m × 2m Transonic Wind Tunnel, there have been more needs of wind tunnel users for high measurement accuracy to develop aircraft and launch vehicles with high performance. The thermal zero shift of strain-gage balance output caused by an unfavorable increase of flow temperature during a run influences the repeatability of the balance measurement. To reduce and correct the thermal zero shift, a preheating method is established. Moreover, a balance, whose outputs are not easily affected by the temperature change, is developed to recover data productivity. Furthermore, to improve prediction accuracy of flight results from force measurement data, effects of the wall and the support interference need to be corrected precisely in consideration of the mutual interference. Relations of both effects are analyzed by comparisons between wind tunnel data of a calibration model and CFD data of the model. The support interference correction on the basis of the CFD results is applied to the wind tunnel data.