環型噴嘴超音速流場數值模擬分析

Numerical Analysis of Supersonic Flow Field Simulation of Ring Nozzle

宋承翰(Song Cheng-Hang)

指導教授 ： 蔡建雄 ； 陳彩蓉

國立屏東科技大學/工學院/車輛工程系所/碩士(2023年)

https://doi.org/10.6346/NPUST202300050

摘要

本研究主要探討不同噴嘴流道設計及不同材料參數對於粒徑大小的影響。研究使用Ansys/Fluent針對三種不同噴嘴流道設計(內縮2 mm、水平0 mm、凸出4 mm)進行流場分析，首先分析不同邊界是否會影響模型流場，分析結果對於流場氣體最大速度相差0.003 %，但是流線上截然不同，要符合現實實驗須以兩側為牆壁。
針對內縮2 mm、水平0 mm、凸出4 mm噴嘴在不同進氣壓力下進行模擬，結果得知，隨進氣壓力增大，氣流所產生的迴流區越大，三種噴左設計達到尾流閉鎖壓力分別為48 bar、50 bar、57 bar，增加粒徑進行模擬，內縮2 mm與凸出4 mm在發生尾流閉鎖後平均粒徑有上升趨勢，推測是噴嘴設計及氣體出口與撞擊點距離很長，動能損失較多，而水平0 mm平均粒徑整體呈現變小趨勢。
針對粒徑在不同溫度、不同表面張力以及不同材料下進行模擬分析，結果顯示，以溫度來看，隨著粒徑溫度越高，平均粒徑呈現變小趨勢。以表面張力來看，材料表面張力越小所產生的平均粒徑越小，反之越大。以不同材料方面來看，模擬粒子溫度設定為1100 ℃，在此溫度下， 銅進入流場溫度快速降至熔點溫度1080 ℃以下，粒徑平均較大，材料鋁與材料錫因熔點低，粒徑平均較小。

關鍵字

計算流體力學 ； 數值模擬 ； 環形噴嘴

並列摘要

This study focuses on the effect of different nozzle runner designs and different material parameters on the particle size. The study uses Ansys/Fluent to analyze the flow field for three different nozzle runner designs (2 mm internal shrinkage, 0 mm horizontal, and 4 mm projection), and first analyzes whether different boundaries affect the model flow field.
Simulations were conducted for 2mm inlet, 0mm horizontal, and 4mm projection nozzles at different inlet pressures, and the results showed that as the inlet pressure increases, the larger the backflow area generated by the gas flow, and the three nozzle designs reach the wake closure pressure of 48 bar, 50 bar, and 57 bar, respectively, and increase the particle size for simulation, the average particle size of 2mm inlet and 4mm projection in the wake closure has increased It is presumed that the nozzle design and gas exit distance from the impact point are very long, which results in more kinetic energy loss, while the overall average particle size of 0mm is decreasing.
The simulations were conducted for different temperatures, different surface tensions and different materials, and the results showed that, in terms of temperature, the average particle size tends to decrease as the temperature of the particle size increases. In terms of surface tension, the lower the surface tension of the material, the smaller the average particle size produced, and vice versa. In terms of different materials, the melting point of copper is 1080 °C, and the particle temperature is set to 1100 °C. Under this temperature, the temperature of copper entering the flow field drops rapidly to below 1080 °C, and the average particle size is large.

並列關鍵字

Computational fluid mechanics ； numerical simulation ； annular nozzles

參考文獻

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