Effects of Mach Number and Magnetic Fields on Performance of MHDG in Nozzle

Abstract

The technique of magnetohydrodynamic (MHD) power generation has attracted a lot of interest as a potential means of improving the effectiveness and performance of hypersonic vehicle. Therefore, in current research the flow characteristics of the hypersonic vehicle nozzle with a magnetohydrodynamic generator (MHDG) at different incoming Mach numbers were analyzed to understand the effect of different parameters on the performance. The results showed that when the entrance incoming Mach number was below 1.1, the thermal choking effect occurred at the entrance of nozzle, so that reduction in the real Mach number is required to a certain value before the weakly ionized gas (WIG) entered the nozzle. As the value of entrance incoming Mach number approaches to 1.1, the thermal choking effect was strengthened at the nozzle entrance and the entrance real Mach number was descended, the power generation efficiency and the enthalpy extraction rate were declined. On the contrary, as value of entrance incoming Mach number exceeded 3, the entrance real Mach number became equal to the entrance incoming Mach number due to the absence of thermal choking, the power generation efficiency remained unaffected with the rise of the entrance incoming Mach number. Additionally, the power generation efficiency decreased as the magnetic field increased when the entrance incoming Mach number was set to 1.1, however, when the entrance incoming Mach number was set to 3, the effect of the magnetic field on the power generation efficiency vanished, and the power generation efficiency remained constant as the magnetic field increased.

Keywords

• mhdg
• entrance incoming mach number
• magnetic field
• power generation efficiency
• enthalpy extraction rate