Design optimisation factors for axial turbine stators in small-scale geo-solar powered Brayton applications

IF 6.7 2区工程技术 Q1 ENGINEERING, AEROSPACE

Propulsion and Power Research Pub Date : 2026-06-01 Epub Date: 2026-07-03 DOI:10.1016/j.jppr.2026.06.002

Ahmed M. Daabo, Ali Basem, Mudasar Zafar, Nabeel M. Abdulrazzaq, Fadhel N. Al-Mousawi, Omar Rafae Alomar, Qusay R. Al-Amir, Abdulelah H. Yaseen, Tawfik Badawy

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Abstract

Small axial turbines for geo-solar Brayton cycles require stator designs that are efficient and robust, yet systematic guidance on how detailed stator airfoil geometry influences performance in this power range remains limited. This study quantifies the sensitivity of stator and stage performance to fourteen geometric parameters defining the stator airfoil and derives practical design guidance for small-scale geo-solar Brayton cycles in the 20–70 kW range. A reference axial turbine stage is first generated using mean-line design, followed by three-dimensional blade modelling and meshing using BladeGen and TurboGrid. Steady-state, three-dimensional compressible flow simulations are performed in ANSYS CFX employing the SST k-ω turbulence model. Each stator geometric parameter is varied individually within realistic bounds while all other parameters are held at baseline values. Stator losses, stator efficiency, and total-to-total stage efficiency are evaluated across a range of pressure ratios (PR = 2–4). Numerical accuracy is ensured through grid refinement, y-plus control, and comparison with independent experimental data from the literature. The results show a clear hierarchy of geometric influence. Four parameters, namely trailing edge wedge angle, trailing edge thickness, and two parameters governing the rear suction side contour, dominate performance, causing up to 5% variation in stator efficiency and about 2% variation in stage efficiency at higher pressure ratios. At PR = 3, the best configuration increased stator efficiency from 88.36% to 92.31% and total to total stage efficiency from 83.46% to 85.32%. Reducing the rear suction side parameter F13 from 50 to 20 mm increased stage efficiency from 82.70% to 85.76% at PR = 2 and reduced the nozzle loss coefficient from 0.757 to 0.377. Overall, most efficiency variation is governed by a small subset of geometric features, indicating that near optimal performance can be achieved with simplified stator geometries when these key parameters are selected carefully.

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设计优化因素的轴向涡轮定子在小型地太阳能供电布雷顿应用

小型轴向涡轮地太阳布雷顿循环需要定子设计是高效和稳健的，但系统的指导如何详细的定子翼型几何形状影响性能在这个功率范围内仍然有限。该研究量化了定子和级性能对确定定子翼型的14个几何参数的敏感性，并为20-70 kW范围内的小型地太阳布雷顿循环提供了实用的设计指导。参考轴向涡轮级首先使用平均线设计生成，然后使用BladeGen和TurboGrid进行三维叶片建模和网格划分。采用SST k-ω湍流模型，在ANSYS CFX中进行了稳态、三维可压缩流动模拟。每个定子几何参数在实际范围内单独变化，而所有其他参数保持在基线值。定子损耗、定子效率和总级效率在一系列压力比（PR = 2-4）下进行评估。通过网格细化、y +控制和与文献中独立实验数据的比较，确保了数值精度。结果显示了几何影响的清晰层次。四个参数，即尾缘楔角、尾缘厚度和控制后吸力侧轮廓的两个参数，对性能起主导作用，在高压比下，定子效率变化高达5%，级效率变化约2%。在PR = 3时，最佳配置将定子效率从88.36%提高到92.31%，将总级效率从83.46%提高到85.32%。将后吸力侧参数F13从50 mm降低到20 mm，在PR = 2时，级效率从82.70%提高到85.76%，喷嘴损失系数从0.757降低到0.377。总体而言，大多数效率变化是由一小部分几何特征控制的，这表明当仔细选择这些关键参数时，简化定子几何形状可以实现接近最佳的性能。

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来源期刊

Propulsion and Power Research Multiple-

CiteScore

7.50

自引率

5.70%

发文量

期刊介绍： Propulsion and Power Research is a peer reviewed scientific journal in English established in 2012. The Journals publishes high quality original research articles and general reviews in fundamental research aspects of aeronautics/astronautics propulsion and power engineering, including, but not limited to, system, fluid mechanics, heat transfer, combustion, vibration and acoustics, solid mechanics and dynamics, control and so on. The journal serves as a platform for academic exchange by experts, scholars and researchers in these fields.