in the centrifugal compressor the function of the volute or the diffuser to convert kinetic energy into pressure energy my question is isnt it bernouuli equation??and we can apply bernouuli equation to incompressible fluid?? also wouldnt that cause an exapnsion to fluid which causes reduction in presuure?? also the lecturere told us that in multi stage compressors the diamters get smaller so expansion wouldnt happen so i can mainatain high pressure ?? so i see contadiction about that i hope if you can clarfiy that.i feel so confused.