This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Examinations of a Lysholm CompressorS Performance and the Engine Performance Supercharged By the Lysholm Compressor
Published November 03, 1998 by Institution of Mechanical Engineers in United Kingdom
The Lysholm Compressor as one of the types of mechanical superchargers has characteristics in having an internal compression. This internal compression enables high pressure ratio and highly efficient supercharging.
Performance of the Lysholm Compressor can be changed according to its parameters. For example, if the internal pressure ratio is lower than boost pressure, driving power of the Lysholm Compressor can be changed by declining the internal pressure ratio in unloading conditions. On the contrary, highly efficient supercharging can be attained by increasing internal pressure ratio when high boost pressure is required.
We investigated simulation results of engine performance of the hybrid supercharging (two-stge supercharging by a turbocharger and Lysholm Compressor) for a heavy-duty diesel engine as an example of using this Lysholm Compressor.
In this paper, we investigated an 8.8 L diesel engine to confirm the effect brought by the Lysholm Compressor which begins high boost pressure from the low engine speed range. The hybrid supercharging has the characteristics that the Lysholm Compressor makes high boost pressure in the low engine speed range and ensures sufficient air volume in that range. Torque increase and smoke reduction can be expected there. With these features, the hybrid supercharging system has been considered as an effective method for the smoke of diesel engines, which has been strictly regulated recently from the environmental point of view in each country.
Besides, the flat torque characteristics of a hybrid- supercharged engine is quite similar to the torque characteristics of a naturally aspirated engine. The highly supercharged torque brought by the Lysholm Compressor in the low engine speed range is approximately double to that obtained by a turbocharger alone, so that displacement volume of the base engine can be made small. And it is possible to match the turbocharger in high engine speed range. From the above, the hybrid supercharging system is considered to be an engine supercharging system with various possibilities.