How to find efficiency of the engine

To find the efficiency of any engine, find the ratio of completed work to spent on this energy. It is known two basic types of engines used by man – the internal combustion engine and the electric motor. Measuring efficiency first, useful work divide for the total heat released during the combustion of fuel, and the second count is spent executing useful work electricity and find their attitude.

You will need

• characteristics of the internal combustion engine, the load of known weight and tester.

Instruction

1. Determination of the efficiency of the engine internal samoraneniya in the technical documentation of power of the engine of internal combustion. Fill it with fuel, it can be gasoline or diesel fuel, and get to work on maximum rpm some time, measure with a stopwatch, in seconds. Drain excess and determine the volume of burnt fuel, subtracting from the original volume is finite. Find its mass by multiplying the volume transferred in m3, the density in kg/ m3.
2. To determine efficiency capacity of the engine multiply by time and divide by the product of the mass of spent fuel by its specific combustion heat efficiency=P•t/(q•m). To get the result in percent, the resulting number and multiply by 100.
3. If you want to measure the efficiency of the engine of the vehicle, and the power of his unknown, but the known mass to determine the useful work will accelerate it from rest to a speed of 30 m/s (if possible) by measuring the mass of spent fuel. Then the car's weight, multiply the square of its velocity, and divide by twice the product of the mass of spent fuel on the specific heat of its combustion efficiency=M•v2/(2•q•m).
4. The definition of efficiency electroengine If one knows the power of electroengine, then connect it to the power supply with a known voltage, maximize speed tester, measure the current in the circuit. Then, the power divide by the product of the current and voltage efficiency=P/(I•U).
5. If the power of the engine is unknown, attach to its shaft a pulley, and lift at a known altitude, a known mass of cargo. Measure with a tester the voltage and amperage on the engine, but in the same time lifting. Then the product of the mass of the load to the lifting height and the number of 9.81 divide by the product of voltage, current and rise time in seconds efficiency=m•g•h/(I•U•t).