HYDRODYNAMICS AND ACOUSTICS

2019 ◊ Volume 1 (91) ◊ Issue 4 ◊ p. 408-424

K. N. Kuzmenko^*, N. F. Yurchenko^*, P. M. Vinogradskii^*, Yu. O. Paramonov^*

^* Institute of Hydromechanics of NAS of Ukraine, Kyiv, Ukraine

Optimization of construction and work of gas aspirator

Gidrodin. akust. 2019, 1(4):408-424

TEXT LANGUAGE: Russian

ABSTRACT

Aspirators are critical elements of modern automotive passenger safety systems, providing maximum airbag inflation in a minimum time not exceeding 30 ms. In fact, these devices are supersonic gas ejectors. A comprehensive numerical-experimental study of aspirator models was done to optimize its design. To increase the flow rate and the aspiration coefficient, the results of numerical simulation of the tests of three variants of the aspirator design were analyzed, including the modification of the mixing chamber. The article presents the results of experiments on a pneumatic installation designed especially for this work. Its distinguishing feature is the presence of a system for measuring the ejection process at the outlet and in the internal path of the aspirator. A new universal high-speed valve UHSV16-1, the central element of the experimental setup, was developed, manufactured, and tested. The pressures of flow separation from the aspirator's wall are recorded depending on the pressure at its inlet. The optimal parameters of the aspirator operation and the design variant that satisfy the task conditions were found. It is shown that flow separation preventing an increase in air flow occurs with excessive inlet pressure. Therefore, operation at a pressure 1...2 bar below the breakaway threshold is recommended. The optimized aspirator is designed to be smaller than the original model. In particular, its diameter and length are reduced by 10 mm.

KEY WORDS

aspirator, airbag, pressure, airflow

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