This paper presents the validation of a coupled hybrid (1D/3D-CFD) modelling methodology, using FDS version 6.7.5, for the first time, with full-scale fire tests. Real fire conditions of the Runehamar tests with maximum heat release rates of 6 MW, 66 MW, and 119 MW are compared by assessing temperature profiles, centreline velocity, backlayering lengths, and maximum temperatures at different locations both upstream and downstream from the fire source. An expression to evaluate the length of the 3D domain where the fire is located is successfully assessed. Also, a pressure boundary condition at one of the portals is suggested to predict more precisely the inner flow conditions. The temperature profiles are accurately predicted with time-averaged differences lower than 20% beyond 40 m downstream from the fire source in the three tests. Furthermore, with the coupled hybrid approach, the backlayering length is estimated accurately with the fire of 66 MW and underestimated in the 6 MW and 119 MW fires, i.e. a maximum difference lower than 4% of the total tunnel length. The validated proposed methodology allows accurate predictions of temperature for tunnel fires and reduces the computational cost between 27% and 75% with respect to a full-CFD numerical model.

本文介绍了耦合混合 (1D/3D-CFD) 建模方法的验证，首次使用 FDS 版本 6.7.5 进行全面火灾测试。通过评估火源上游和下游不同位置的温度曲线、中心线速度、背层长度和最高温度，比较了最大热释放速率为 6 MW、66 MW 和 119 MW 的 Runehamar 测试的真实火灾条件。成功评估了用于评估火灾所在的 3D 域长度的表达式。此外，建议使用其中一个入口处的压力边界条件来更准确地预测内部流动条件。在三个测试中，在火源下游 40 m 以外的时间平均差异低于 20%，准确预测了温度剖面。此外，使用耦合混合方法，在 66 MW 的火灾中准确估计了背层长度，而在 6 MW 和 119 MW 的火灾中被低估了，即最大差异低于隧道总长度的 4%。经验证的提议方法允许准确预测隧道火灾的温度，并相对于全 CFD 数值模型将计算成本降低 27% 至 75%。