Mileage Accumulation Dynamometer Testing

For rapid, cost-effective automotive testing, Southwest Research Institute (SwRI) offers around-the-clock mileage accumulation at speeds up to 100 miles per hour. To complement its fleet testing capabilities, the Institute has installed 20 mileage accumulation dynamometers (MADs), that accommodate most cars and light trucks up to 7,000 pounds. Virtually any transient or steady-state driving cycle can be accurately reproduced in this facility.

Using this equipment, SwRI can evaluate the durability and performance of various automotive fluids, fuels, components, and emission control systems. MAD testing offers:

• Transient and steady-state driving cycles
• Controlled and repeatable tests
• No downtime for adverse weather
• Side-by-side component comparisons
• Efficient multiple component testing
• Safe operations
• Convenient and real-time access to test data
• Ability to test prototype systems that are not yet roadworthy

The Institute's mileage accumulation dynamometer facility provides rapid, cost-effective vehicle testing, accommodating more than 20 cars or light trucks.

Constant speed electric motors are coupled with clutches to provide transient motoring capability and inertia simulation. A 100-hp power absorption dynamometer provides speed control, load control, and braking. The vehicle drive wheels transmit power to the MADs through 48-inch diameter rolls. The computer-controlled throttle actuator consistently follows specified driving cycles. Each unit is equipped with a 61,000 cfm blower to provide wind speed equivalent to roll speed. This configuration accurately reproduces the underhood and underbody temperatures experienced by the engine, drivetrain, and exhaust systems under normal driving conditions. In addition, each MAD unit is connected to a 500-gallon underground fuel tank for continuous operation on gasoline. LPG, methanol, diesel or other alternative fueled vehicles can also be operated on the MADs.

For additional information, please contact:

Larry A. Eckhardt, Manager

The Institute has also installed a 48-inch roll dynamometer to evaluate vehicle emissions under high acceleration rates, high loads, and high speeds, in addition to standard emissions and fuel economy test cycles. In conjunction with the 48-inch roll emissions dynamometer, SwRI has a Horiba modal analysis system that provides emission test results on a second-by-second basis. The Horiba system utilizes three analytical benches: an engine-out or before-catalyst bench, an after-catalyst bench, and a dilute exhaust bench. By combining the large roll dynamometer with the modal analysis system, the Institute can comprehensively evaluate fuel, fuel additive, and exhaust aftertreatment effects on vehicle exhaust emissions.

For additional information, please contact:

Daniel Stewart, Director

Division Publications

Fuels Performance Evaluations
Fuels and Driveline Lubricants Research Department
Fuels and Lubricants Research Division
SwRI Technical Divisions SwRI Home

November 06, 2009