Aerodynamic Drag Reduction

3/10-Scale Double Stack Container Cars National Research Council of Canada 30' x 30' Wind Tunnel Aerodynamic Force Measurements for Cross Winds of 0° to 90°

Abstract

Fluid dynamics models were employed to quantify the drag implications of two external railcar design features: 1) inter-railcar gags and 2) railcar side posts. The effects of various design modifications on train resistance and fuel usage were evaluated. 

Objectives

An engineering design study was undertaken to Reduce Aerodynamic Resistance of Well-Type Intermodal Cars. The specific car models evaluated during this project are manufactured by The Greenbrier Companies.


Features of Car Design Included in the Study

1) Smooth Side vs. Exposed Side Posts

Rail Car with Smooth Sides

Rail Car with Exposed Side Struts

2) Inter-Car Spacing

Husky Stack Well-Type Intermodal Car

Maxi Stack Well-Type Intermodal Car

Approach

• Utilize Wind Tunnel Tests and CFD Models to Quantify Drag Effects of Design Modifications
• Evaluate Effect of Drag Reductions on Train Fuel Consumption using Association of American Railroads (AAR) AERO Program

Wind Tunnel Testing 3/10-Scale Well-Car Wind Tunnel Tests

CFD Modeling CFD Results of Smooth and Exposed Side Strut Cars

Simulation Results

Surface Pressures Smooth Side Exposed Side Struts

Velocities            Smooth Side                                           Detail of Flow at Side Post    Exposed Side Struts                                            Drag Area Results

Results and Conclusions

Drag


Fuel Consumption

• Fuel Consumption per 1,000 Miles for Intermodal Train:
• 5 Locomotives, Twenty 5-Unit Well Cars (200 48’ Containers)
• Total Train Weight: 15,942,000 pounds

Effect of Gap