A two dimensional mathematical model was developed to predict the performance characteristics for direct current, linear channel MHD propulsion system in a closed loop environment. The results of analytical and exper...A two dimensional mathematical model was developed to predict the performance characteristics for direct current, linear channel MHD propulsion system in a closed loop environment. The results of analytical and experimental studies of the linear channel MHD propulsor are described. Compared with the data of experiment, the correctness of the computation program is validated.展开更多
In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model o...In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model of the flow is developed and the analytical results are obtained for both the cylindrical and Cartesian configurations that are proper to use in the propulsion of marine vessels. The governing parabolic momentum PDEs are transformed into an ordinary differential equation using approximate velocity distribution. The numerical results are obtained and asymptotic analyses are built to discover the mathematical behavior of the solutions. The maximum velocity in a magneto-hydro-dynamic pump versus time for various values of the Stuart number, electro-magnetic interaction number, Reynolds number, aspect ratio, as well as the magnetic and electrical angular frequency and the shift of the phase angle is presented. Results show that for a high Stuart number there is a frequency limit for stability of the fluid flow in a certain direction of the flow. This stability frequency is dependent on the geometric parameters of a channel.展开更多
The flow loss of a helical channel Magnetohydrodynamic （MHD） thruster without MHD effect was numerically studied with 3-D simulations, and a flow loss coefficient （ was defined to quantify the flow loss and its inf...The flow loss of a helical channel Magnetohydrodynamic （MHD） thruster without MHD effect was numerically studied with 3-D simulations, and a flow loss coefficient （ was defined to quantify the flow loss and its influencing factors were studied. The results show that （ decreases in a first-order exponential manner with the pitch of a helical wall and the Reynolds number, and it declines slowly when t / T 〉 0.2 and Re 〉 10^5, a flow guide makes the flow more smooth and uniform, especially in the flow guide and helical wall sub-regions and thus reduces the flow loss greatly, by about 30% with the averaged value of （ from 0.0385 to 0.027, a rectifier weakens the helical flow and strengthens the axial one in the rectifier and outlet sub-regions, thus reduces the rotational kinetic pressure with the averaged value of ξ declining about 4% from 0.0385 to 0.037, and ξ decreases with a rectifier＇s axial length when Re 〉 10^5 .展开更多
文摘A two dimensional mathematical model was developed to predict the performance characteristics for direct current, linear channel MHD propulsion system in a closed loop environment. The results of analytical and experimental studies of the linear channel MHD propulsor are described. Compared with the data of experiment, the correctness of the computation program is validated.
文摘In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model of the flow is developed and the analytical results are obtained for both the cylindrical and Cartesian configurations that are proper to use in the propulsion of marine vessels. The governing parabolic momentum PDEs are transformed into an ordinary differential equation using approximate velocity distribution. The numerical results are obtained and asymptotic analyses are built to discover the mathematical behavior of the solutions. The maximum velocity in a magneto-hydro-dynamic pump versus time for various values of the Stuart number, electro-magnetic interaction number, Reynolds number, aspect ratio, as well as the magnetic and electrical angular frequency and the shift of the phase angle is presented. Results show that for a high Stuart number there is a frequency limit for stability of the fluid flow in a certain direction of the flow. This stability frequency is dependent on the geometric parameters of a channel.
文摘The flow loss of a helical channel Magnetohydrodynamic （MHD） thruster without MHD effect was numerically studied with 3-D simulations, and a flow loss coefficient （ was defined to quantify the flow loss and its influencing factors were studied. The results show that （ decreases in a first-order exponential manner with the pitch of a helical wall and the Reynolds number, and it declines slowly when t / T 〉 0.2 and Re 〉 10^5, a flow guide makes the flow more smooth and uniform, especially in the flow guide and helical wall sub-regions and thus reduces the flow loss greatly, by about 30% with the averaged value of （ from 0.0385 to 0.027, a rectifier weakens the helical flow and strengthens the axial one in the rectifier and outlet sub-regions, thus reduces the rotational kinetic pressure with the averaged value of ξ declining about 4% from 0.0385 to 0.037, and ξ decreases with a rectifier＇s axial length when Re 〉 10^5 .
