This paper aims to introduce the core features of the Fuzzy Logic (FL) approach in simulations of turbulent Supersonic flows as a cost-effective methodology. Computational Fluid Dynamic (CFD) analysis is conducted to study the effect of Mach number (M e ), nozzle pressure ratio (NPR) and expansion corners (EC) on primary recirculation region length (Xr1). An Open FOAM numerical solver was used for this purpose. The CFD results developed were focused on developing relationships between input and output using the Mamdani-based fuzzy logic approach. This approach used membership functions viz. Triangular, Generalized bell shape and Gaussian membership functions. The models developed were matched with confirmatory test cases which differ from the training data. The flow field contours showed that the flow field generated numerous intrinsic features in the corner vortex. Also, the Triangular membership function made better predictions than the other two functions as it had a least absolute percentage error of 9.0705%.

中文翻译：

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使用 CFD 和模糊逻辑研究突然膨胀的超声速流的再循环区域长度

本文旨在介绍模糊逻辑 (FL) 方法在湍流超音速流动模拟中的核心特征，作为一种具有成本效益的方法。进行计算流体动力学 (CFD) 分析以研究马赫数 (Me)、喷嘴压力比 (NPR) 和膨胀角 (EC) 对初级再循环区域长度 (Xr1) 的影响。为此使用了 Open FOAM 数值求解器。开发的 CFD 结果侧重于使用基于 Mamdani 的模糊逻辑方法开发输入和输出之间的关系。这种方法使用了隶属函数，即。三角、广义钟形和高斯隶属函数。开发的模型与不同于训练数据的验证性测试用例相匹配。流场轮廓表明流场在角涡中产生了许多内在特征。此外，三角隶属函数比其他两个函数做出了更好的预测，因为它的绝对百分比误差最小为 9.0705%。