Test study of performance of electronic scanivalve system

Abstract

Electronic scanivalve system is an important measuring equipment for fluctuating wind pressure in wind tunnel tests, and its stability and accuracy may be affected by many factors. Based on wind tunnel tests, one study was undertaken on the characteristics of signals collected with an electronic scanivalve system with conditions of natural ambient excitations, small and medium perturbation excitations, environmental temperature changes, sudden pipeline blockage and alterations in pipeline length and curvature. The analysis was also performed on the degrees of various factors' effect upon signals and the specific reasons. The results show that under white noise excitations such as natural ambient excitations, small and medium interferences and so on, the average pressure basically equals zero and the standard deviation of pressure increases with excitation intensity growing, therefore it is strongly recommended to avoid the vibration of acquisition system and the model. The effect of ambient temperature changes on pressure cannot be ignored, so it is suggested that the environmental temperature difference should not be too large during the test period. Pipeline blockage will make pressure signals alter suddenly and become stable gradually. And increases in pipeline length and curvature can intensify the fluctuating signal distortion, therefore it is proposed that the pipeline should be as short and straight as possible, and the pipeline entanglement with small radiuses should be avoided.