|Table of Contents|

Effect of backpressure on liquid film thickness of close-end swirl injector(PDF)

《火箭推进》[ISSN:1672-9374/CN:CN 61-1436/V]

Issue:
2023年03期
Page:
83-89
Research Field:
目次
Publishing date:

Info

Title:
Effect of backpressure on liquid film thickness of close-end swirl injector
Author(s):
GAO Qixiang1;  SUN Hu1;  WANG Huanran2;  YANG Lijun1;  FU Qingfei1
(1. Beihang University, School of Astronautics, Beijing 100191, China 2. Xian Aerospace Propulsion Institute, Xian 710100, China)
Keywords:
swirl injector film thickness backpressure conductance method empirical formula
PACS:
V434
DOI:
-
Abstract:
The liquid film thickness of swirl injector is one of the main parameters affecting the atomization effect of the injector. In this paper, the effect of different back pressures on the thickness of liquid film in close-end swirl injector was studied. By setting up a back pressure injection system, the liquid film thickness of close-end swirl injector was measured by conductivity method, and the obtained voltage value was calibrated by ceramic needle gauge to obtain the liquid film thickness value. The uncertainty of liquid film thickness is 0.017 mm. The injection environment was provided for the nozzle through the high-pressure chamber, and the liquid film thickness under different injection pressure drop and backpressure was measured. It is concluded that the liquid film thickness of swirl injector tends to become thinner with the increase of injection pressure drop. The increase of backpressure will increase the gas density, intensify the friction between the air vortex and the liquid film interface in the swirl injector, reduce the liquid velocity, and make the liquid film thickness thicker under the same mass flow rate. The accuracy of the measurement results was verified by comparing the liquid film thickness under atmospheric pressure with the estimated value of empirical formula. Based on the existing theoretical formula of liquid film thickness, a new empirical formula of liquid film thickness is proposed by introducing the backpressure term.

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