 flow field diffus radial compressor flow field diffus radial compressor note discuss two-dimension diffus flow field radial compressor impel wheel assum diffus guid vane arrang circular row radiu impel wheel radiu fig 1 flow diffus start circl radiu veloc compon direct veloc vector circl prescrib thermal ga flow prescrib radiu disturb boundari condit flow veloc infin fulfil develop spiral flow 