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

Abstract

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.

Effects of Guide Vane Placement Angle on Hydraulic Characteristics of Flow Field and Optimal Design of Hydraulic Capsule Pipelines

“…The horizontal pipe model was divided into three sections: an inlet pipe, a movement pipe and an outlet pipe, where the lengths of these three sections were 0.5, 4.8, and 0.5 m respectively. The 0.5 m long inlet pipe was used in order to allow the pipe fluid to become fully developed [13]. A 0.5 m long outlet pipe can be used to reduce the effects of transporting the piped carriage on the pressure distributions of the outlet cross-section in the mathematical model.…”

“…Polderman et al [11] explored the hydraulic characteristics for the lubricating fluid in the annular slit areas when the single cylindrical capsule was moving within the pipelines, and compared three-layer gradient diffusion models with the experimental results. Chow [12] and Sud et al [13] extended Kroonenberg's [10] studies. They analyzed the fully developed turbulent flow models within the annular slit areas under the moving boundary by adopting basic relationships of the turbulent flow.…”

Hydraulic Characteristics of Transporting a Piped Carriage in a Horizontal Pipe Based on the Bidirectional Fluid-Structure Interaction

“…Garg [27], Ogawa et al [28], and Kroonenberg [29] introduced respective friction coefficients between the moving capsule wall and the pipe wall and established mathematical models of transporting a concentric cylindrical capsule within the pipelines. Flow characteristics of both the developing and the fully developed annular slit flows were estimated by Sud et al [30] and Tomita et al [31], through studying fundamental relationships between the turbulent flow and Von Karman's similarity hypothesis [24] in an idealized model of a highspeed ground transportation system. Their studies were restricted to bidimensional flow conditions.…”