Quantitative Analysis of Flow Resistance in the Ventilation Pipeline of Ejection Seats and Optimization Design of Flow Resistance Reduction
摘要
During normal flight, the ejection seat ventilation system provides a dedicated gas transmission channel for electronic oxygen and anti load regulators. The flow resistance of the pipeline directly affects the ventilation and supply performance of the regulator and the anti load protection ability during mobile operations. This article adopts a combination of numerical simulation and experimental testing methods to quantitatively analyze the flow resistance of a certain type of ejection seat ventilation pipeline. Based on the principle of gas supply performance testing and numerical simulation methods, a research process is designed. The simulation accuracy of different simulation models under different ventilation flow rates is analyzed, and the ventilation pipeline is optimized based on the calculation formula of pipeline flow resistance theory and the analysis results of pipeline flow field. The research results indicate that among multiple turbulence models, the Realizable k-e model has the best accuracy in simulating pipeline flow resistance, with a maximum error of 14.2% and a minimum error of 1.3% under different flow conditions, both below 15%, meeting the requirements for engineering use; the vortices generated at the corners and variable diameter areas of the ventilation pipeline can lead to energy dissipation. Optimizing the transition corners and pipeline diameter of the bend can reduce the generation of vortices and reduce the system flow resistance to 17.9% of the original value; under the premise of constant pipeline flow rate, the flow resistance of ventilation pipelines is inversely proportional to the fifth power of pipeline diameter. When optimizing pipeline flow resistance design, emphasis should be placed on optimizing from the pipeline diameter.