Numerical and Low-Order Modelling of Double Wall Liner Cooling With Pin-Fins

Abstract One of the most widely used cooling schemes is double-wall cooling, which combines the effectiveness of impingement and effusion cooling techniques. While double-wall cooling offers significant advantages in terms of thermal management, the structural integrity of this configuration must also be considered. The pressure differential across a double-wall structure can vary significantly during flight missions, necessitating the use of pin fins between the walls to enhance structural stability. Additionally, these pin fins contribute to cooling performance by increasing the wetted surface area and enhancing internal turbulence levels. However, as cooling geometries become increasingly complex, the time required to model and predict metal temperatures also increases significantly. Accurate prediction of metal temperatures and flow distribution is critical for the overall engine design process, and these predictions must be achieved efficiently, without excessive computational time or iterations. To address this challenge, low-order models are essential for providing reliable predictions of metal temperatures and accurate flow distribution within the engine. In this study, a low-order model is developed for double-wall cooling schemes incorporating pin-fin geometries, building on the framework established in GT2024-129340: Development of a Reduced Order Model for Double Wall Liner Cooling Schemes. In addition to the previous work, the model is enhanced to account for heat loss from the effusion plate due to the presence of pin fins. Several test cases under varying blowing ratios are modelled and compared with experimental data to validate the accuracy and reliability of the low-order model.