A modified numerical model for predicting long-term wind-induced snowdrift on building roofs within the multistage quasi-steady method

To accurately predict the long-term wind-induced snowdrift on building roofs, this study developed a modified numerical model within the multistage quasi-steady simulation method. A novel method was introduced to estimate prototype blowing snow duration based on wind tunnel experimental data, and a boundary mesh adaptive technique combined with the bounded radial basis function interpolation method was implemented to track dynamic boundary changes during snow drifting. Additionally, the influence of temporal parameters, including blowing snow duration, time allocation schemes, and number of stages, was systematically analyzed through the multistage quasi-steady simulation method, with validation conducted using wind tunnel experiments. The results indicate that when Anno's time similarity parameters were used to estimate the blowing snow duration for the prototype roof, the simulation results derived from the proposed methodology closely aligned with the experimental results, outperforming the previously used empirical formulas for snow transport rates. Generally, when the blowing snow duration is fixed, increasing the number of stages enhances the simulation's approximation to the actual snow drifting process; however, an optimal number of stages exists based on convergence conditions and time allocation schemes. Altering the blowing snow duration also affects the optimal number of stages, with longer and shorter durations requiring more and fewer computational stages, respectively. Numerical simulations reveal that as snow drifting progresses, the friction velocity on the roof gradually decreases, reducing the rate of snow erosion per unit of time. Consequently, the mean snow transport rate on the building roof decreases non-linearly over time. The proposed numerical model can offer significant insights for designing snow loads in practical engineering applications.