Understanding better 'artificial total pressure loss' in multi-stage axial-flow compressor

Aim: To our knowledge, owing to computational complexity, previous research that used mixing plane approach was, in our opinion, poor in information about 'artificial total pressure loss'. We now explore the 'artificial total pressure loss' of multistage axial-flow compressor with five blade rows or more. In the full paper, we explain our exploration in some detail; in this abstract, we just add some pertinent remarks to listing the two topics of explanation. The first topic is: Numerical methods. In the first topic, we mention that four step Runge-Kutta time-marching method by Jameson with the central difference scheme is employed to resolve the N-S equations. Also in the first topic, we point out that the flow information between two adjacent rows is exchanged between each other by the mixing-plane approach. The second topic is: Numerical results and their analysis. In the second topic, we give two numerical examples: A 2.5 stage axial-flow compressor and a 3.5 stage one. Figs. 1 through 4 give the numerical results for 2.5 stage compressor and Figs. 5 through 7 give those for the 3.5 stage compressor. The analysis of these results shows preliminarily that; (1) 'The artificial total pressure loss' and the discontinuity of the flowfield occur on the interface between two adjacent rows due to the 'artificial mixing' of the mixing plane approach; (2) The rotational speed of the axial-flow compressor has a distinct influence on the 'artificial total pressure loss'; (3) But for an axial-flow compressor with both rotational speed and pressure ratio low, its aerodynamic performance could be predicted accurately and quickly using the mixing plane method.