Understanding Practical Limits to Heavy Truck Drag Reduction

Understanding Practical Limits to Heavy Truck Drag Reduction

A heavy truck wind tunnel test program is currently underway at the Langley Full Scale Tunnel (LFST). Seven passive drag reducing device configurations have been evaluated on a heavy truck model with the objective of understanding the practical limits to drag reduction achievable on a modern tractor trailer through add-on devices. The configurations tested include side skirts of varying length,...

External Flow Analysis of a Truck for Drag Reduction

Aerodynamics of trucks and other high sided vehicles is of significant interest in reducing road side accidents due to wind loading and in improving fuel economy. Recognizing the limitations of conventional wind tunnel testing, considerable efforts have been invested in the last decade to study vehicle aerodynamics computationally. In this paper, a three-dimensional near field flow analysis has...

Development of Practical Drag Reduction System for District Cooling Systems

In this report, results from the project, proposed in the original research plan are presented. 10 surfactant systems effective as drag reducing agents (DRA’s) in efficient district cooling, including four commercial cationic surfactants, one commercial and three novel synthesized zwitterionic surfactants, one commercial nonionic surfactant and one zwitterionic(synthesized)/anionic surfactant m...

Superposition of drag reduction due to riblets on drag reduction due to polymers

Turbulent Drag Reduction by Spanwise Wall Oscillations

The objective of this paper is to examine the effectiveness of wall oscillation as a control scheme of drag reduction. Two flow configurations are considered: constant flow rate and constant mean pressure gradient. The Navier-Stokes equations are solved using Fourier-Chebyshev spectral methods and the oscillation in sinusoidal form is enforced on the walls through boundary conditions for the sp...