Question 13.5: A MHD generator channel with segmented electrodes (refer to ......
A MHD generator channel with segmented electrodes (refer to Figure 13.9) is operating under the following conditions:
• MHD channel volume is V = 12 m³
• Short-circuit current density J_{sc} of 11,000 A/m²
• Electrical resistivity ρ of the ionized gas is 0.032 Ω m
• Load factor K is 0.6
• Product of gas velocity and magnetic field strength: uB = 352 V/m (under the short-circuit conditions with load factor K = 0).
Calculate (i) the MHD generator power output, and (ii) the actual current density in the MHD channel.
1. Power output of MHD generator with channel volume V = 12 m³ and K = 0.6.
2. Actual current density in the MHD channel
J=(1-K)u \,B/{\bf r}=(1-0.6)352\,\mathrm{V/ m}/0.032\,\mathbf{\Omega}\,\mathrm{ m}=4400\,\,\mathrm{A/m^{2}}Calculation of power output and energy conversion efficiency of the Faraday MHD generator is presented in Example 13.6.