Purpose

The purpose of this study is to model steam condensing flows through steam turbine blades and find the most suitable condensation model to predict the condensation phenomenon.

Design/methodology/approach

To find the most suitable condensation model, five nucleation equations and four droplet growth equations are combined, and 20 cases are considered for modelling the wet steam flow through steam turbine blades. Finally, by the comparison between the numerical results and experiments, the most suitable case is proposed. To find out whether the proposed case is also valid for other boundary conditions and geometries, it is used to simulate wet steam flows in de Laval nozzles.

Findings

The results indicate that among all the cases, combining the Hale nucleation equation with the Gyarmathy droplet growth equation results in the smallest error in the simulation of wet steam flows through steam turbine blades. Compared with experimental data, the proposed model’s relative error for the static pressure distribution on the blade suction and pressure sides is 2.7% and 2.3%, respectively, and for the liquid droplet radius distribution it totals to 1%. This case is also reliable for simulating condensing steam flows in de Laval nozzles.

Originality/value

The selection of an appropriate condensation model plays a vital role in the simulation of wet steam flows. Considering that the results of numerical studies on condensation models in recent years have not been completely consistent with the experiments and that there are still uncertainties in this field, further studies aiming to improve condensation models are of particular importance. As condensation models play an important role in simulating the condensation phenomenon, this research can help other researchers to better understand the purpose and importance of choosing a suitable condensation model in improving the results. This study is a significant step to improve the existing condensation models and it can help other researchers to gain a revealing insight into choosing an appropriate condensation model for their simulations.

中文翻译：

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寻找合适的冷凝模型来模拟湿蒸汽跨音速流动

目的

本研究的目的是对通过汽轮机叶片的蒸汽冷凝流进行建模，并找到最合适的冷凝模型来预测冷凝现象。

设计/方法论/途径

为了找到最合适的冷凝模型，结合了五个成核方程和四个液滴生长方程，并考虑了 20 种情况来模拟通过汽轮机叶片的湿蒸汽流。最后，通过数值结果与实验的比较，提出最合适的情况。为了查明所提出的情况是否也适用于其他边界条件和几何形状，它被用来模拟拉瓦尔喷嘴中的湿蒸汽流。

发现

结果表明，在所有情况下，将Hale成核方程与Gyarmathy液滴生长方程相结合，在湿蒸汽流经汽轮机叶片的模拟中误差最小。与实验数据相比，该模型对于叶片吸力侧和压力侧静压分布的相对误差分别为2.7%和2.3%，对于液滴半径分布的相对误差总计为1%。该案例对于模拟拉瓦尔喷嘴中的冷凝蒸汽流也是可靠的。

原创性/价值

选择合适的冷凝模型对于湿蒸汽流动的模拟起着至关重要的作用。考虑到近年来凝结模型的数值研究结果与实验并不完全一致，该领域还存在不确定性，进一步改进凝结模型的研究显得尤为重要。由于凝结模型在模拟凝结现象中发挥着重要作用，因此本研究可以帮助其他研究人员更好地理解选择合适的凝结模型对改善结果的目的和重要性。这项研究是改进现有凝结模型的重要一步，它可以帮助其他研究人员深入了解如何选择合适的凝结模型进行模拟。