MHD EFFECTS CAUSED BY INSULATOR COATING IMPERFECTIONS

The imperfections of insulator coating in the MHD duct inner wall may be caused by microcrack or flaking. In this paper, the results of MHD pressure drop measurements in the presence of insulator coating flakin g are presented. Those results are directly measured from transmitter and from outer wall voltage distribution and calculated from an analyt ical model. The results of microcrack effect on MHD pressure drop from the analytical model prediction are also included in this paper. The results showed that a very small microcrack in insulator coating cause d additional MI-ID pressure drops, higher than those produced by the s ame length duct with perfect insulator coating. (C) 1998 Elsevier Scie nce S.A. All rights reserved.