Numerical Simulation of Operation Optimization of Coalfired MHD Generator Using Genetic Algorithms

The study on the application of Genetic Algorithms(GA) to numerical simulation has been carried out. The simulation with GA is aimed at to realize the operation optimization of the coal fired MHD generator channel. The computer program for this purpose has been developed. By simulating numerically the operation optimization of IEE’s 25MWt coal fired experimental MHD generator, the feasibility of the application of GA procedure to the MHD power generation field has been verified.

The Particularities of Coal-fired MHD Generators

This paper describes the particularities of coal-fired MHD generators in two aspects: the pysical phenomena near the electrode and the mathematical modeling.

Theoretical Investigation of Operation Modes of MHD Generators for Energy-bypass Engines

A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inner mechanism of operation modes.For the MHD generator with a uniform constant magnetic field,a specific critical electric field E_(cr) is required to decelerate a supersonic entrance flow into a subsonic exit flow.Otherwise,the generator works in a steady mode with a larger electric field than E_(cr) in which a steady supersonic flow is provided at the exit,or the generator works in a choked mode with a smaller electric field than E_(cr) in which the supersonic entrance flow is choked in the channel.The detailed flow field characteristics in different operation modes are discussed,demonstrating the relationship of operation modes with electromagnetic fields.

Performance investigation of plasma magnetohydrodynamic power generator

A magnetohydrodynamic （MHD） power generator system involves several subjects such as magnetohydrodynamics, plasma physics, material science, and structure mechanics. Therefore, the performance of the MHD power generator is affected by many factors, among which the load coefficient k is of great importance. This paper reveals the effect of some system parameters on the performance by three-dimensional （3D） numerical simulation for a Faraday type MHD power generator using He/Xe as working plasma. The results show that average electrical conductivity increases first and then decreases with the addition of magnetic field intensity. Electrical conductivity reaches the maximum value of 11.05 S/m, while the applied magnetic field strength is B = 1.75 T. When B 〉 3 T, the ionization rate along the midline well keeps stable, which indicates that the ionization rate and three-body recombination rate （three kinds of particles combining to two kinds of particles） are approximately equal, and the relatively stable plasma structure of the mainstream is preserved. Efficiency of power generation of the Faraday type channel increases with an increment of the load factor. However, enthalpy extraction first increases to a certain value, and then decreases with the load factor. The enthalpy extraction rate reaches the maximum when the load coefficient k equals 0.625, which is the best performance of the power generator channel with the maximum electricity production.

A blowup criterion for the 3D generalized MHD system with zero magnetic diffusivity

This paper proves a new regularity criterion ω: = rotu∈L1(0,T;B·0∞,∞) for the 3D generalized MHD system with fractional diffusion terms(-Δ)αu with α >9/8 and zero magnetic diffusivity. Here u is the fluid velocity,ω is the vorticity and B·0∞,∞is the homogeneous Besov space.

Dynamics for Controlled 2D Generalized MHD Systems with Distributed Controls

We study the dynamics of a piecewise （in time） distributed optimal con- trol problem for Generalized MHD equations which model velocity tracking coupled to magnetic field over time. The long-time behavior of solutions for an optimal dis- tributed control problem associated with the Generalized MHD equations is studied. First, a quasi-optimal solution for the Generalized MHD equations is constructed; this quasi-optimal solution possesses the decay （in time） properties. Then, some prelimi- nary estimates for the long-time behavior of all solutions of Generalized MHD equa- tions are derived. Next, the existence of a solution of optimal control problem is proved also optimality system is derived. Finally, the long-time decay properties for the opti- mal solutions is established.

Global Well-posedness of Generalized Magnetohydrodynamics Equations in Variable Exponent Fourier–Besov–Morrey Spaces

A generalized incompressable magnetohydrodynamics system is considered in this paper.Furthermore, results of global well-posednenss are established with the aid of Littlewood–Paley decomposition and Fourier localization method in mentioned system with small initial condition in the variable exponent Fourier–Besov–Morrey spaces. Moreover, the Gevrey class regularity of the solution is also achieved in this paper.