Direct Energy Conversion: An Overview of Stanley W. Angrist's Book
Direct energy conversion is the process of converting one form of energy into another without intermediate steps or losses. It is a topic of great interest and importance for both science and engineering, as it offers the potential for more efficient and sustainable energy production and utilization.
One of the most comprehensive and authoritative books on direct energy conversion is Direct Energy Conversion by Stanley W. Angrist, a professor of mechanical engineering at the University of Michigan. First published in 1976 and revised in 1982, this book covers the principles, applications, and challenges of various methods of direct energy conversion, such as magnetohydrodynamics, thermoelectrics, thermionics, photovoltaics, and fission fragment collection.
In this article, we will provide a brief summary of each chapter of Angrist's book, highlighting the main concepts and examples of direct energy conversion. We will also discuss some of the advantages and disadvantages of each method, as well as the current state and future prospects of research and development in this field.
Chapter 1: Introduction
This chapter introduces the concept and history of direct energy conversion, as well as some general considerations for evaluating the performance and feasibility of different methods. Angrist defines direct energy conversion as \"the conversion of one form of energy into another without any intermediate steps involving heat engines or electric generators\". He also distinguishes between primary and secondary energy sources, and between reversible and irreversible processes.
Angrist traces the origins of direct energy conversion to the discovery of electromagnetism by Faraday and Oersted in the early 19th century, and the subsequent development of electric motors and generators. He also mentions some early attempts at direct energy conversion, such as Seebeck's thermoelectric effect, Edison's thermionic emission, Becquerel's photovoltaic effect, and Crookes' radiometer.
Angrist then discusses some criteria for comparing different methods of direct energy conversion, such as efficiency, power density, cost, reliability, environmental impact, and compatibility with existing systems. He also introduces some basic thermodynamic concepts and equations that are relevant for analyzing direct energy conversion processes.
Chapter 2: Magnetohydrodynamic Power Generation
This chapter deals with magnetohydrodynamic (MHD) power generation, which is the direct conversion of thermal or kinetic energy of a conducting fluid (such as plasma or liquid metal) into electrical energy by means of a magnetic field. Angrist explains the physical principles and mathematical models of MHD power generation, as well as some practical aspects such as electrode design, heat transfer, shock waves, ionization, and Hall effect.
Angrist also describes some examples of MHD power generation systems, such as open-cycle MHD generators (which use combustion gases or nuclear reactors as heat sources), closed-cycle MHD generators (which use liquid metals or molten salts as working fluids), disk MHD generators (which use rotating disks to create relative motion between fluid and magnetic field), and MHD accelerators (which use MHD to propel rockets or spacecraft).
Angrist evaluates the advantages and disadvantages of MHD power generation, such as high efficiency, low pollution, scalability, simplicity, high temperature requirements, electrode erosion, plasma instability, and low power density. He also discusses some current challenges and future prospects of MHD research and development.
Chapter 3: Thermoelectric Power Generation
This chapter covers thermoelectric power generation, which is the direct conversion of heat into electricity by means of a temperature difference across a junction of two dissimilar materials. Angrist explains the physical principles and mathematical models of thermoelectric power generation,
such as Seebeck effect (which generates voltage from temperature difference), Peltier effect (which generates heat or cooling from current flow), Thomson effect (which generates heat or cooling from temperature gradient along a conductor), and figure-of-merit (which measures the efficiency
of a thermoelectric material).
Angrist also describes some examples of thermoelectric power generation systems,
such as thermocouples (which consist of pairs of junctions connected in series),
thermopiles (which consist of multiple thermocouples connected in series or parallel),
thermionic converters (which use thermionic emission to create 0efd9a6b88