The effects of boundary layer phenomena on the performance of disk CCMHD generator
The effects of boundary layer phenomena on the performance of disk CCMHD generator
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边界层现象对盘式CCMHD发生器性能的影响
DOI：
10.1109/27.376566
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发表时间：
1995
影响因子：
1.5
通讯作者：
S. Kabashima
中科院分区：
文献类型：
--
作者：
T. Suekane;K. Yoshikawa;S. Kabashima
通过二维计算，研究了闭式循环MHD （CCMHD）发生器的边界层行为及其对其性能的影响，并探讨了焓萃取率与绝热效率之间的关系。计算结果表明，由于电动势较小，较大的洛伦兹力会导致逆流流动的边界层传播和分离。对于大负载电阻，边界层变得很厚，涡流在大范围内产生。在本例发电机中，当洛伦兹力使工作气体减速到马赫数在1.0 ~ 1.5之间时，工作气体对洛伦兹力的推力功有效地转化为电能。滞止压力损失随负载阻力增大而增大，直至焓萃取比达到最大值。由于焦耳加热和粘度引起的熵产随着负载阻力的增加而增加。焓萃取比和绝热效率取最大值的负载阻力之间的差异可以用焦耳加热和粘度的熵产来解释。>
Two dimensional calculations were carried out to clarify the behavior of boundary layer and its effects on performance of closed cycle MHD (CCMHD) generator and to investigate the relation between enthalpy extraction ratio and adiabatic efficiency. Calculation results suggest that the large Lorentz force causes propagation and separation of boundary layer where reverse current flows, because of small electromotive force. For large load resistance boundary layer becomes very thick and the eddy current arises in broad region. The push work of working gas against Lorentz force is effectively converted into electric energy under the condition at which the Lorentz force decelerates the working gas to Mach number in the range between 1.0 and 1.5 in this case of the generator. Stagnation pressure loss increases with load resistance until enthalpy extraction ratio takes maximum value. The entropy production due to Joule heating and viscosity increases with load resistance. The difference between the load resistances for which the enthalpy extraction ratio and the adiabatic efficiency take maximum value can be explained with the entropy production of Joule heating and viscosity. >