Drag Calculations for Vehicles in Very Long Tubes From Turbulent Flow Theory

Fundamental turbulent flow techniques are used to examine the annular fluid flow occurring in an idealized model of a high speed ground transportation system. The model consists of a smooth cylindrical train moving in an infinitely long tunnel, creating an annular gap with one wall in motion. The developing, and the fully developed, flow regions are separately analyzed by using fundamental relations of turbulent flow and Von Karman’s similarity hypothesis. The relevant equations are developed and numerical solution procedures presented. Limited sample calculations show good agreement with existing empirical and experimental results.