利用一组铷-铁-硼强铁磁体和电极组成的电磁极阵列,在海水平板湍流边界层中产生具有一定穿透深度的电磁力,实验研究了行波式洛伦兹力(Traveling-Wave-Like Lorentz Force )对湍流边界层快慢条带的影响,氢气泡流动显示表明在电磁力的影响...利用一组铷-铁-硼强铁磁体和电极组成的电磁极阵列,在海水平板湍流边界层中产生具有一定穿透深度的电磁力,实验研究了行波式洛伦兹力(Traveling-Wave-Like Lorentz Force )对湍流边界层快慢条带的影响,氢气泡流动显示表明在电磁力的影响下,湍流边界层底层快慢条带相干结构出现间距是平均值2～3倍的低速区域,低速条带的统计平均间距明显增大.展开更多
This work reports the effects of magnetic field on an electrically conducting fluid with low electrical conductivity flowing in a smooth expanded channel. The governing nonlinear magnetohydrodynamic （MHD） equations ...This work reports the effects of magnetic field on an electrically conducting fluid with low electrical conductivity flowing in a smooth expanded channel. The governing nonlinear magnetohydrodynamic （MHD） equations in induction- free situations are derived in the framework of MHD approximations and solved numerically using the finite-difference technique. The critical values of Reynolds number （based on upstream mean velocity and channel height） for symmetry breaking bifurcation for a sudden expansion channel （1：4） is about 36, whereas the value in the case of the smooth expansion geometry used in this work is obtained as 298, approximately （non-magnetic case）. The flow of an electrically conducting fluid in the presence of an externally applied constant magnetic field perpendicular to the plane of the flow is reduced significantly depending on the magnetic parameter （M）. It is expansion （1：4） is about 475 for the magnetic parameter M found that the critical value of Reynolds number for smooth = 2. The separating regions developed behind the smooth symmetric expansion are decreased in length for increasing values of the magnetic parameter. The bifurcation diagram is shown for a symmetric smoothly expanding channel. It is noted that the critical values of Reynolds number increase with increasing magnetic field strength.展开更多
This paper presents the results of exact solutions and numerical simulations of strongly-conductive and weakly-conductive magnetic fluid flows. The equations of magnetohydrodynamic (MHD) flows with different conductiv...This paper presents the results of exact solutions and numerical simulations of strongly-conductive and weakly-conductive magnetic fluid flows. The equations of magnetohydrodynamic (MHD) flows with different conductivity coefficients, which are independent of viscosity of fluids, are investigated in a horizontal rectangular channel under a magnetic field. The exact solutions are derived and the contours of exact solutions of the flow for magnetic induction modes are compared with numerical solutions. Also, two classes of variational functions on the flow and magnetic induction are discussed for different conductivity coefficients through the derived numerical solutions. The known results of the phenomenology of magnetohydrodynamics in a square channel with two perfectly conducting Hartmann-walls are just special cases of our results of magnetic fluid.展开更多
文摘利用一组铷-铁-硼强铁磁体和电极组成的电磁极阵列,在海水平板湍流边界层中产生具有一定穿透深度的电磁力,实验研究了行波式洛伦兹力(Traveling-Wave-Like Lorentz Force )对湍流边界层快慢条带的影响,氢气泡流动显示表明在电磁力的影响下,湍流边界层底层快慢条带相干结构出现间距是平均值2～3倍的低速区域,低速条带的统计平均间距明显增大.
基金support by the UGC(SAP),DSA-I in the Mathematics Department,Burdwan University,India
文摘This work reports the effects of magnetic field on an electrically conducting fluid with low electrical conductivity flowing in a smooth expanded channel. The governing nonlinear magnetohydrodynamic （MHD） equations in induction- free situations are derived in the framework of MHD approximations and solved numerically using the finite-difference technique. The critical values of Reynolds number （based on upstream mean velocity and channel height） for symmetry breaking bifurcation for a sudden expansion channel （1：4） is about 36, whereas the value in the case of the smooth expansion geometry used in this work is obtained as 298, approximately （non-magnetic case）. The flow of an electrically conducting fluid in the presence of an externally applied constant magnetic field perpendicular to the plane of the flow is reduced significantly depending on the magnetic parameter （M）. It is expansion （1：4） is about 475 for the magnetic parameter M found that the critical value of Reynolds number for smooth = 2. The separating regions developed behind the smooth symmetric expansion are decreased in length for increasing values of the magnetic parameter. The bifurcation diagram is shown for a symmetric smoothly expanding channel. It is noted that the critical values of Reynolds number increase with increasing magnetic field strength.
文摘This paper presents the results of exact solutions and numerical simulations of strongly-conductive and weakly-conductive magnetic fluid flows. The equations of magnetohydrodynamic (MHD) flows with different conductivity coefficients, which are independent of viscosity of fluids, are investigated in a horizontal rectangular channel under a magnetic field. The exact solutions are derived and the contours of exact solutions of the flow for magnetic induction modes are compared with numerical solutions. Also, two classes of variational functions on the flow and magnetic induction are discussed for different conductivity coefficients through the derived numerical solutions. The known results of the phenomenology of magnetohydrodynamics in a square channel with two perfectly conducting Hartmann-walls are just special cases of our results of magnetic fluid.
