Time dependent r-z two dimensional numerical simulation has been carried out in order to clarify the MHD flow behavior and the performance of the disk MHD generator installed in the new closed loop experimental facility at Tokyo Institute of Technology. The main components of the facility are a compressor, a recuperator, a high temperature gas heater, a seed injection system, a superconducting magnet, a disk shaped MHD generator, a cooler, a gas purification system (1) . This paper is focused on the region of the disk MHD generator, shown in Fig. 1, that is here investigated for the first time. In particular, the numerical analysis, that uses a large eddy simulation (LES) model to describe the turbulence of the compressible flow, wants to clarify (1) the behavior of non-MHD flow and MHD flow in the disk MHD generator, and (2) its typical performance in the closed loop experimental facility.The results show that separation of boundary layers occurs in the downstream part of the generator channel both for non-MHD flow and MHD flow. For the MHD effect, the streamlines tend to widen in the generator channel, with reduction of the thickness of non-MHD flow separation zones, as shown in Fig. 2. Furthermore, the MHD flow presents separation of the boundary layer in the anode region due to the large Lorentz Force.The performances of the disk MHD generator have been studied using several load resistances and three seed fractions, as shown in Fig. 3. The load resistances with which the maximum enthalpy extraction ratio (E.E.) and isentropic efficiency (I.E.) can be extracted, shifts to lower value as the seed fraction increases. Best performance are obtained for R L = 0.2 Ω and s f = 8 × 10 −4 . In this case, for thermal input of 0.43 MW, an enthalpy extraction ratio of 19% and isentropic efficiency of 37% are achieved in the studied disk MHD generator.The results obtained in this paper will be fruitful to prepare as better as possible and to assure the success of the future MHD closed loop power generation experiment. However, as soon as the
MemberHiroyuki Yamasaki * Member R-z two dimensional numerical simulation with a large eddy simulation (LES) model has been carried out in order to clarify, for the first time, the typical MHD flow behavior and the performance of the disk MHD generator installed in the new closed loop experimental facility at Tokyo Institute of Technology. The results show thick separated flow regions in the generator channel both for non-MHD flow and MHD flow. The separated region influences the MHD interaction because of its low electrical conductivity. The MHD flow streamlines, however, tend to widen in the generator channel, with reduction of thickness of non-MHD flow separation. The typical performance of the generator have been predicted for several load resistances and seed fractions. The study is important to prepare as better as possible and to assure the success of the future MHD power generation experiment.