Practical work report in engineering school - ENSAIS - on an experimental motor with variable parameters.
Purpose of the TP
The purpose of this TP is to highlight the influence on the behavior of a thermal engine of 3 parameters of fundamental settings:
-the advance to ignition,
the compression ratio.
The tests are of course on a variable parameter, the other 2 fixed. We will highlight for each parameter the influence it has on:
-the specific consumption,
-the overall yield
These are similar tests which are carried out by the manufacturers on the test benches during the final design phase of an engine, in order to determine the electronic control settings (advance curve, injection curve, etc.).
Of course, they take into account many more parameters, such as temperature resistance.
The Tp is carried out on an experimental single-cylinder engine of the French Institute of Petroleum IFP on which we have the following adjustment possibilities
- richness adjustment (carburetor)
- ignition advance adjustment (rotation of the ignition coil)
- adjustment of the compression ratio (experimental cylinder head with variable rate by translation)
The developed torque is absorbed by a Froude hydraulic brake. With the speed of rotation, the useful power is obtained directly. The power supplied is given by the flow of air and gasoline respectively measured by a diaphragm located on the air supply line (pressure difference between the inlet and the outlet in mm of water column) and by measuring the flow time (given volume of 100 mL located on the fuel line).