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Governing Equations of Fluid Mechanics and Heat Transfer
Published in Dale A. Anderson, John C. Tannehill, Richard H. Pletcher, Munipalli Ramakanth, Vijaya Shankar, Computational Fluid Mechanics and Heat Transfer, 2020
Dale A. Anderson, John C. Tannehill, Richard H. Pletcher, Munipalli Ramakanth, Vijaya Shankar
Magnetohydrodynamics (MHD) involves the behavior of electrically conducting fluids in the presence of magnetic and electric fields. The term was coined by Hannes Alfven, who was awarded a Nobel Prize in physics (1970) for his fundamental research on the interactions between plasma and magnetic fields. Magnetic and electric fields are governed by Maxwell’s equations of electromagnetodynamics, which consist of two vector and two scalar equations. In order to compute MHD flows, it is necessary to solve simultaneously both the Navier–Stokes equations and Maxwell’s equations of electromagnetodynamics. Both compressible and incompressible MHD flows are encountered in practice, and present numerous complexities in mathematical model development as well as physical understanding. The textbook by Davidson (2017) provides a thorough and modern presentation of the subject, while the classic text by Sutton and Sherman (1965, 2006) contains a systematic presentation of gas dynamic aspects. MHD as the dynamics of ionized gases or plasma is prominently encountered in astrophysics and in the study of magnetic confinement devices for power generation by nuclear fusion. Incompressible MHD flows of liquid metals are seen in metallurgy, and in advanced concepts for power extraction in magnetic confinement nuclear fusion.
Alternative Energy Systems/More Green Possibilities
Published in Dale R. Patrick, Stephen W. Fardo, Ray E. Richardson, Brian W. Fardo, Energy Conservation Guidebook, 2020
Dale R. Patrick, Stephen W. Fardo, Ray E. Richardson, Brian W. Fardo
MHD stands for magnetohydrodynamics, a process of generating electricity by moving a conductor of small particles suspended in a superheated gas through a magnetic field. The process is illustrated in Figure 12-8. The conductors are made of metals, such as potassium or cesium, and can be recovered and used again. The gas is heated to a temperature much hotter than the temperature to which steam is heated in conventional power plants. This superheated gas is in what is called a plasma state. This means that the electrons of many of the gas atoms have been stripped away to make the gas a good electrical conductor. The combination of gas and metal is forced through an electrode-lined channel which is under the influence of a superconducting magnet that has tremendous strength. The magnet must be of the superconducting type since a regular electromagnet of that strength would require too much power. A superconducting magnet is one of the key parts to this type of generation system.
Alternative Power Systems
Published in Stephen W. Fardo, Dale R. Patrick, Electrical Power Systems Technology, 2020
Stephen W. Fardo, Dale R. Patrick
MHD stands for magnetohydrodynamic, a process of generating electricity by moving a conductor of small particles suspended in a superheated gas through a magnetic field. The process is illustrated in Figure 5-5. The metallic conductors are made of metals such as potassium or cesium, and can be recovered and used again. The gas is heated to a temperature much hotter than the temperature to which steam is heated in conventional power plants. This superheated gas is in what is called a plasma state at these high temperatures. This means that the electrons of many of the gas atoms have been stripped away, thus making the gas a good electrical conductor. The combination of metal and gas is forced through an electrodelined channel which is under the influence of a superconducting magnet that has a tremendous field strength. The magnet must be of the superconducting type, since a regular electromagnet of that strength would require too much power. A superconducting magnet, therefore, is one of the key parts to this type of generation system.
Numerical study on magnetohydrodynamics micropolar Carreau nanofluid with Brownian motion and thermophoresis effect
Published in International Journal of Modelling and Simulation, 2023
Advanced technology in a driven world attracts investigators to focus their study on non-Newtonian fluids with heat transfer past stretching sheets due to their tremendous applications in scientific and engineering fields. Energy production, space cooling, copper wire thinning, paper production, elastic sheet cooling, annealing, fiber technology, and extrusion processes are a few essential applications of non-Newtonian fluids past stretching sheets with heat transfer effect [1]. Also, magnetohydrodynamics (MHD) is extensively used in many areas like petroleum production, polymer industries, agriculture engineering, bio-engineering, pumps, etc. Further, as the cooling rate is an essential factor that corresponds to product quality, MHD fluid flows are utilized in the process of manufacturing to control the cooling rate. Thus, the investigation of MHD fluid flows has become a topic of current interest. Reddy et al. [2] have investigated the impacts of irregular and frictional heat on MHD Maxwell and Casson fluid flows over a stretching sheet. The boundary layer MHD flow of a power-law fluid is carried out by Cortell [3] numerically. Shateyi and Muzara [4] have inspected the heat transfer behavior and MHD flow of Williamson fluid and showed that magnetic parameter and Williamson number decline the fluid flow.
Simulation of entropy and heat and mass transfer in Water-EG based hybrid nanoliquid flow with MHD and nonlinear radiation
Published in Numerical Heat Transfer, Part A: Applications, 2023
Satya Subha Shree Sen, Ruma Mahato, Sachin Shaw, Mrutyunjay Das
Magnetohydrodynamics (MHD) is a process where an electrically conducting fluid when influenced by a magnetic field during its flow, changes its poles thereby polarizing itself and affecting the behavior of the fluid. MHD has a variety of applications in different fields. It is used to study the properties of geophysics, chemical technology, reactors and many more. MHD is formed by the combined aspects of Navier Stokes equations and Maxwell equations. Raptis et al. [18] measured the impacts of thermal radiation on fluid flow with MHD effects. Hayat et al. [19] analyzed the influence of magnetic field along with Dufuor and Soret effects on Casson fluid flow. Magnetic field effects on heat and mass transfer rate of a double-diffusive Casson fluid flow in porous medium was analyzed by Das et al. [20]. Shoaib et al. [21] studied the properties of neuro computing under radiation and magnetic effects for entropy generation. Chabani et al. [22] studied the nature of MHD for hybrid nanofluid flow in triangular enclosure with elliptical and zigzag obstacles. Nandi et al. [23] did a quadratic regression analysis of hybrid nanofluid flow moving toward a stagnation point with MHD and radiative effects. Abbas et al. [24] studied the effects of induced MHD and radiation over a nonliear stretching cylinder. Nadeem et al. [25] studied the effects of Lorentz force on micropolar fluid flow over a exponentially stretching sheet. Amjad et al. [26] analyzed the influence of Lorentz force on Casson micropolar nanofluid flow over stretching/shrinking surface.
A Proposed Hybrid Model for Electric Power Generation: A Case Study of Rajasthan, India
Published in IETE Journal of Research, 2023
Parag Nijhawan, Manish Kumar Singla, Jyoti Gupta
Due to the variable nature of renewable in nature, the storage of excess energy is also an important aspect that is to be taken care of. Lead or lithium-ion battery elements are not environment-friendly and are self-discharging in nature; therefore, fuel cell is the best alternative. The efficiency of PEMFC around 70% is achievable by using the mixed solution of produced energy and recovered heat, i.e. not more efficient than battery system [18]. A magneto-hydrodynamic (MHD) generator, similar to a regular generator, generates electricity by revolving a conductor over a magnetic field. Instead of copper, hot conductive plasma is used as the moving conductor [19]. MHD generators are one of the scientists’ initiatives to eliminate mechanical systems working in between thermal and electrical energy conversion, with a view to reduce the loss associated with thermodynamic conversion. As there is no MHD generator in the HOMER Pro system, the generator set is considered the MHD generator as efficiency, construction, and maintenance cost are similar except the emission part. It does not release any emission in the environment. The efficiency of MHD energy system is nearly equal to a conventional power plant i.e. up to 60% [20]. Figure 9 represents the graph between the cumulative nominal cash flow and year. Table 3 represents the economic metrics in which internal rate of return, return of investment, and simple payback year have been calculated.