Design of a High-Bandwidth, Low-Cost Hydrostatic Absorption Dynamometer with Electronic Load Control 2009-01-2846
A low-cost hydrostatic absorption dynamometer has been developed for small to medium sized engines. The dynamometer was designed and built by students to support student projects and educational activities. The availability of such a dynamometer permits engine break-in cycles, performance testing, and laboratory instruction in the areas of engines, fuels, sensors, and data acquisition. The dynamometer, capable of loading engines up to 60kW at 155Nm and 3600rpm, incorporates a two-section gear pump and an electronically operated proportional pressure control valve to develop and control the load. A bypass valve permits the use of only one pump section, allowing increased fidelity of load control at lower torque levels. Torque is measured directly on the drive shaft with a strain gage. Torque and speed signals are transmitted by an inductively-powered collar mounted to the dynamometer drive shaft. Pressure transducers at the pump inlet and pump outlet allow secondary load measurement. Oil temperature is regulated by controlling water flow through a brazed plate heat exchanger. The electronically operated proportional pressure control valve provides capability to automate engine load cycles for test repeatability and ease of operation. With the low rotary inertia and electronic pressure control, it is possible to achieve good transient control of the torque load on the engine.