Engine Operation Points and Performance

JSLY

Me, pictured in front of modified Volvo B5254 engine with Dynamometer (blue machine box, behind engine) and a variety of different testing apparatuses (everywhere). MIT Sloan Automotive Laboratory.

Today was another well-spent afternoon hanging out in the Sloan Automotive Lab! Our class split into two groups and my group spent the afternoon collecting data for the engine operation lab. The lab had two components. The first half of the lab was focused on measuring the MAP, NIMEP, Fuel Pressure, COV of GIMEP, and exhaust temperature of the engine when different spark timings were used. The Air-Fuel Ratio was held constant at stoichiometric for these tests. The dry exhaust gas was collected and the concentration of NOx, CO, HC, CO2 in the gas was measured. The second half of the lab varied the Air-Fuel Ratio and the spark timing was constant (the Max Brake Torque spark timing was used). The same measurements were collected. All in all, it was a cool experience and I welcomed the chance to spend the afternoon in the Sloan Automotive Lab. It’s a bummer 2.61 (Internal Combustion Engines) only had two labs! I still need to process all the data and do a lab write-up. I’ll post some scans  of the data and the resulting write-up later.

The Volvo engine on its mount with test apparatus and dynamometer. The engine is in a separate room while these tests are run. All of the data readouts are either outside of the room  or visible through the window made of protective glass.

The Volvo engine on its mount with test apparatus and dynamometer.

The engine controls and data readouts are kept outside of the room with the engine, engine mount and test apparatuses. A shatterproof window allowed visual access to the engine and the test apparatuses while providing protection to the engine operators.

Exahust composition readout

Inside of engine room, on the left is the drying and collection apparatus for the exhaust gas. This exhaust gas is collected so that the concentration of NOx, CO, HC, and CO2 are measured. CO, HC, and CO2 values are displayed on the screen.

The exhaust gas from the engine is collected so that the concentration of NOx, CO, HC, and CO2 are measured. CO, HC, and CO2 values are displayed on the screen.

Exahust composition readout (COLOR)

The red box shows the collection and drying setup. The purple box shows the readout screen.

The dynamometer for the operation of the engine. The dynamometer measures the power outputted by the motor. The dynamometer is part of the control loop for the motor operation that ensure the motor operates at a specified condition so that the motor's behaviors can be studied at that operation point.

The dynamometer for the operation of the engine. The dynamometer measures the power outputted by the motor. The dynamometer is part of the control loop for the motor operation that ensure the motor operates at a specified condition so that the motor’s behaviors can be studied at that operation point.

The controls for the engine. The throttle controls are highlighted in the red box and the other controls are in the purple box. The readout screens are for various temperature and pressure sensors.

The controls for the engine. The throttle controls are highlighted in the red box and the other controls are in the purple box. The readout screens are for various temperature and pressure sensors.

The lambda meter measures the air-to-fuel ratio of the engine.

The lambda meter measures the air-to-fuel ratio of the engine. At stoichiometric, this ratio is 1 and the value of lambda is 1.

Most of the sensors output directly to the computers. One computer operates the engine (communicating with the dynamometer and the engine control unit) while the other gathers data on engine operation.

Most of the sensors output directly to the computers. One computer operates the engine (communicating with the dynamometer and the engine control unit) while the other gathers data on engine operation.

And that’s it! When I finish the lab report I’ll post the data and some of the conclusions I reached.

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