Laminar-turbulent transition flow can be observed in thermal engineering applications, but the flow resistance and heat transfer characteristics are not fully understood. In this work, flow and heat transfer for the laminar-turbulent transition in a rectangular channel were predicted by a four-equation transition turbulent model. A set of correlations for the heat transfer coefficient in a rectangular channel were developed and implemented in the RELAP5/MOD3.1 code to make it capable of analyzing a plate-type fuel assembly with rectangular coolant channels. The improved RELAP5/MOD3.1 code was employed to analyze the SBLOCA along with the SBO scenario for an integrated pressurized reactor, illustrating the effects of model modification on the evolution of the accident.

在热工程应用中可以观察到层流湍流，但是对流动阻力和传热特性还没有完全了解。在这项工作中，通过四方程过渡湍流模型预测了矩形通道中层流湍流的流动和传热。开发了一组矩形通道内传热系数的相关性，并在RELAP5 / MOD3.1代码中实现，使其能够分析带有矩形冷却剂通道的板式燃料组件。改进的RELAP5 / MOD3.1代码用于分析集成加压反应堆的SBLOCA和SBO情景，从而说明了模型修改对事故演变的影响。