Cooling Fan Selection in Power Car Application: CFD/FEA Coupled Approach

This paper describes the methodology used to select application based fan that has optimum operating characteristics in terms of cooling air flow rate, fan power, noise and structural strength. The process uses 1D one-way CFD-FEA coupling approach in highly non-uniform actual flow field inside application. As part of different fan evaluation, full rail coach Underhood simulations were carried out using steady state 3D computational fluid dynamics (CFD) approach. For each fan option fan power, air flow rate and surface acoustic power is evaluated. Pressure profiles on fan blades are studied to assess effect of non-uniform downstream air passage designs. Surface acoustic power is calculated using Broadband noise source model in Fluent. Finite Element Analysis simulation is done in Ansys. Surface pressure profiles over fan blades are imported from 3D CFD are used in finite element analysis (FEA) simulations. Analyses are carried out blade linear and non-linear properties. Equivalent fully reversed stress is calculated based on Goodman program. It can be concluded from simulation study that, CFD-FEA coupled approach can be used to predict and optimize machine cooling system performance with optimum fan selection in design phase itself, thus reducing product design-cycle, re-work cost with increased reliability which is utmost important for rail application.