The objective of the D-SEND#2 flight test was to demonstrate the validity of JAXA’s low sonic boom design concept through the balloon drop technique which was used in the D-SEND#1 tests. Although the first flight test of the D-SEND#2 test vehicle was conducted in the 16th of August, 2013, the test was unfortunately failure. In order to solve the main cause of the failure, JAXA improved the stability and control system of the vehicle by including corrected aerodynamic data. The second flight test was successfully conducted in the 24th of July, 2015, and lots of data of the sonic boom generated by the vehicle were measured with our special microphone system. The remarkable reduction of both front and rear overpressure of the sonic boom measured at the design condition was clearly confirmed. However, the waveform of its pressure distribution (called “pressure signature”) was not precisely similar to the low boom pressure signature estimated on the vehicle which was developed with the JAXA’s low boom design concept. After the detail analysis of its difference, JAXA found out that the main reason was based on the deformation of pressure signature through its propagation within atmospheric turbulence which was recognized to exist around the region from the ground to altitude of 3km. JAXA newly developed a boom propagation tool including the effect of atmospheric turbulence on the propagation of sonic boom, then confirmed that the difference between the measured and estimated pressure signatures was able to be physically explained by the effect of atmospheric turbulence quantitatively as well as qualitatively. This article provides detailed technical information about the plan and preparation outline, some design results of the vehicle system, and principal results of the D-SEND#2 flight test.
内容記述
形態: カラー図版あり
内容記述（英）
Physical characteristics: Original contains color illustrations
D-SEND#2 飛行試験報告書
AA1930022000_D.pdf
(504.09MB)
