Purpose

This study aims to present the numerical study on supersonic jet mixing characteristics of the co-flow jet by varying lip thickness (LT). The LT chosen for the study is 2 mm, 7.75 mm and 15 mm.

Design/methodology/approach

The primary nozzle is designed for delivering Mach 2.0 jet, whereas the secondary nozzle is designed for delivering Mach 1.6 jet. The Nozzle pressure ratio chosen for the study is 3 and 5. To study the mixing characteristics of the co-flow jet, total pressure and Mach number measurements were taken along and normal to the jet axis. To validate the numerical results, the numerical total pressure values were also compared with the experimental result and it is proven to have a good agreement.

Findings

The results exhibit that, the 2 mm lip is shear dominant. The 7.75 mm and 15 mm lip is wake dominant. The jet interaction along the jet axis was also studied using the contours of total pressure, Mach number, turbulent kinetic energy and density gradient. The radial Mach number contours at the various axial location of the jet was also studied.

Practical implications

The effect of varying LT in exhaust nozzle plays a vital role in supersonic turbofan aircraft.

Originality/value

Supersonic co-flowing jet mixing effectiveness by varying the LT between the primary supersonic nozzle and the secondary supersonic nozzle has not been analyzed in the past.

中文翻译：

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不同唇厚的超音速协流射流数值分析

目的

本研究旨在通过改变唇厚度 (LT) 对协流射流的超音速射流混合特性进行数值研究。为研究选择的 LT 为 2 毫米、7.75 毫米和 15 毫米。

设计/方法/方法

主喷嘴设计用于提供 2.0 马赫的射流，而辅助喷嘴设计用于提供 1.6 马赫的射流。为研究选择的喷嘴压力比为 3 和 5。为了研究协流射流的混合特性，沿射流轴并垂直于射流轴进行总压力和马赫数测量。为了验证数值结果，还将数值总压力值与实验结果进行了比较，证明具有良好的一致性。

发现

结果表明，2 mm 唇缘剪切占优势。7.75 毫米和 15 毫米的唇缘以尾流为主。还使用总压力、马赫数、湍流动能和密度梯度的等值线研究了沿射流轴的射流相互作用。还研究了射流不同轴向位置处的径向马赫数轮廓。

实际影响

排气喷嘴中不同 LT 的影响在超音速涡扇飞机中起着至关重要的作用。

原创性/价值

过去没有分析通过改变主超音速喷嘴和辅助超音速喷嘴之间的 LT 的超音速共流射流混合效率。