MHD electrical power generation in a T-layer plasma flow

In the present work, magnetohydrodynamics (MHD) power generation based on the T-layer regime has been investigated both experimentally and numerically. The experimental investigation has been carried out in a shock tunnel MHD facility. There, the plasma layer characteristics have been studied. The layers have been produced by means of electrical discharges at the entrance of a segmented Faraday MHD channel. Streak photography pictures and charge coupled device (CCD) camera snap shots are used to observe the layers. The effect of the layers on the local electrical power production is studied through the response of the currents of individual electrode pairs. The performance characteristic of the T-layer MHD generation has been investigated in a channel of commercial size (active length of 14 m) by means of numerical simulations performed by means of a two-dimensional time dependent (2-Dt) model. In the commercial size channel, when using ideal gas and neglecting loss mechanisms, an enthalpy extraction larger than 30% has been obtained. The effects of a real gas and of loss mechanisms on the T-layer MHD conversion have been studied by means of the 2-Dt numerical analysis in a 4-m channel. In this channel, when an ideal gas is used, a reduction of about 20% of the electrical power output is caused by the loss mechanisms. When loss mechanisms and combustion gas in the 4-m channel are considered, an increase of the power stored in the plasma T-layer is observed. This power is of the order of the electrical power extracted from the MHD channel.