後座安全氣囊吸氣式充氣器之設計與分析

The Numerical Analysis and Design of the Aspirated Inflator on Backside Airbag

王長志(Charng-Jyh Wang) ； 宋崗(Kang Sung)

《台北海洋技術學院學報》 2卷1期 (2009/03) Pp. 1-9

https://doi.org/10.29770/JTCMT.200903.0001

摘要

『後座安全氣囊吸氣式充氣器之設計與分析』計畫主要在提供吸氣式後座乘員安全防護氣囊基本構型品設計的方向與建立氣囊內部流場數值模擬分析，計畫中以現有計算流體力學數值方法模擬分析不同幾何形狀之吸氣式充氣模組穩態流場狀態。在一封閉空間中外圍冷空氣可藉由進氣道吸入其中，冷空氣由進氣道被吸入的氣體量會因著噴流流場的流速、週遭環境的溫度與壓力、噴嘴與進氣道的幾何形狀及其相對應的裝置位置等因素而改變。藉由本計畫的數值模擬分析，可獲得最佳吸氣率效能的吸入氣體量、噴嘴與進氣道之幾何大小、裝置位置與噴流流速彼此間的對應關係，以及安全氣囊構型及材質等。如此可使得設計者在設計吸氣式後座乘員安全防護氣囊時，得以達成最佳化的設計。
計畫在硬品方面除精進防後座撞擊吸氣式充氣模組設計，並製作一組充氣之實體可視化觀測模型，精進設計以達成量產為目標，特別對硬品之易製性及減少加工程序等，以Design-in的方式進行量產構型奠基設計及試驗，期能提供業界量產製造。模型試驗中氣體產生器之噴流以高壓氮氣模擬，並對側座簾幕式防護氣囊裝置及後座半球式防護氣囊裝置進行動態觀測，結果可提供模擬及設計參考。

關鍵字

吸氣式充氣模組 ； 安全防護氣囊 ； 計算流體力學

並列摘要

Purpose-The study of the aspirated inflator on backside airbag modulus can provide a new direction for airbag design. The main purpose of this project is to design, model and test a new inflator. Design/methodology/approach-Computational fluid dynamics is used to analyze the supersonic turbulent flow of a gas generator in different geometries. The strong inject flow of gas generator will induce outside cold air to enter into the airbag and cool down the high temperature gas flow.
Findings-The inner flow field changes quickly according to l)gas inject velocity; 2)surrounding air temperature and pressure, and 3)position of jet nozzle and air inlet. The aim of this project is to find an optimum position and geometry for gas generator and inlet opening that can provide a high aspiration ratio for the new design inflator.
Practical implications-Numerical simulation using FLUENT will provide an empirical relation of inject gas nozzle, inlet opening and gas inject velocity. Simultaneously, the flow field of this aspirated inflator can be obtained by numerical calculation without further experimental instrumentation.
Originality/value-The new design of airbag will be effectively modified and improved. The results thus can provide a reference for numerical simulation and design improvement of airbags.

並列關鍵字

Airbag ； Aspirated inflator ； Coanda effect

參考文獻

Knight, D. D.(1977).Numerical Simulation of Realistic High Speed Inlets Using the Navier-Stokes Equations.AIAA J..15(11),1583-1897.

Knight, D. D.(1981).Improved Calculation of High Speed Inlet Flows: Part I. Numerical Algorithm.AIAA J..19(1),34-41.

Chausses, D. S.,Pulliam, T. H.(1981).Two-Dimensional Inlet Simulation Using a Diagonal Implicit Algorithm.AIAA J..19(2),153-159.

Biringen, S.(1984).Numerical Simulation of Two-Dimensional Inlet Flowfields.J. Aircraft.21(4),244-249.

Moeckel, W. E.,Connors, J. F.,Schroeder, A. H.(1975).(Investigation of Shock Diffusers at Mach 1.85, Projecting Single-Shock Cones, NACA-RM-E6K27).