Description
Two- and three-dimensional (2D & 3D) simulations of the aerodynamics of hyperloop-like systems with pods travelling at high speeds in ultra-long tubes require unusually large CPU resources. At best, this significantly limits the number of operational conditions that can be investigated reliably in acceptable time windows. The present paper investigates a possible method of circumventing this problem by configuring 1D methods in such a way that they can provide reliable predictions of far-field flows and of vehicle drag. The method requires preliminary CFD simulations to enable suitable values of 1D resistance coefficients to be obtained. Thereafter, large numbers of operational cases can be investigated at low cost. Supplementary CFD simulations are still required when 2D/3D details need to be estimated in the near-field and prudence will require occasional 2D/3D checks on the 1D predictions, but the overall savings are nevertheless potentially large. The use of a suitably-configured 1D model is illustrated and is assessed by its ability to predict the dependence of drag forces on (i) pod speeds and (ii) pod:tube blockage ratios. It is found that the former can be done with reasonable accuracy, but that dedicated preliminary CFD simulations will be required for each blockage ratio.
