Search Results for energy flow

Hammers and high-energy-rate forging machines are classified as energy-restricted machines as they deform the workpiece by the kinetic energy of the hammer ram. This article provides information on gravity-drop hammers, power-drop hammers, die forger hammers, counterblow hammers, and computer-controlled hammers. It describes the three basic designs of high-energy-rate forging (HERF) machines: the ram and inner frame, two-ram, and controlled energy flow. The article reviews forging mechanical presses, hydraulic presses, drive presses, screw presses, and multiple-ram presses.

Temperature control in heat treating is of paramount importance in maintaining the quality and achieving the desired metallurgical results. This article provides a detailed account of the factors affecting temperature control in heat treating furnaces, with information on temperature control systems, including contact sensors, noncontact sensors, controllers, energy-flow regulators, measurement instruments, and set-point programmers. Common contact sensors include temperature scales, thermocouples, and resistance temperature detectors, whereas optical pyrometers and on-line radiation thermometers fall under the noncontact type. The article describes two types of instrumentation used in heat treating: field test instruments for temperature-uniformity surveys and system-accuracy tests; and controlling, monitoring, and recording instruments for digital instrumentation.

Induction processes for melting and heating of metals belong to the high-energy-consuming industrial processes, and continuous improvement of energy efficiency of competitive melting and heating technologies is of increasing interest. This article discusses the energy demand of various melting processes and the improvements in the efficiency of melting processes in induction crucible furnaces. It provides energetic and ecological comparisons of different furnaces for melting of cast iron and aluminum. The article also describes the energy and power management of induction melting processes.

Microjoining with high energy density beams is a new subject in the sense that the progress of miniaturization in industry has made the desire to make microjoints rapidly and reliably a current and exciting topic. This article summarizes the current state of microjoining with both electron and laser beams. It considers the elementary physical processes such as heat and fluid flow to introduce the reader to the phenomena that affect melting, coalescence, and solidification needed for a successful microweld. The various forces driving (and resisting) fluid flow are analyzed. The article discusses the equipment suitable for microjoining and the metallurgical consequences and postweld metrology of the process. It also provides examples of developmental welds employing laser and electron beam microwelding techniques.

A concise and quantified specification is essential to developing suitable product concepts. This article describes an integrated set of structured methods for identifying the customer population for the product and developing a representation of feature demands. The structured methods include design task probing, customer needs analysis, functional decomposition, and competitive benchmarking for directly mapping customer statements to functional requirements.

This article is a comprehensive collection of formulas and numerical solutions, addressing many heat-transfer scenarios encountered in welds. It provides detailed explanations and dimensioned drawings in order to discuss the geometry of weld models, transfer of energy and heat in welds, microstructure evaluation, thermal stress analysis, and fluid flow in the weld pool.

This article provides a comprehensive review and critical assessment of numerical modeling of heat and mass transfer in fusion welding. The different fusion welding processes are gas tungsten arc welding, gas metal arc welding, laser welding, electron beam welding, and laser-arc hybrid welding. The article presents the mathematical equations of mass, momentum, energy, and species conservation. It reviews the applications of heat transfer and fluid flow models for different welding processes. Finally, the article discusses the approaches to improve reliability of, and reduce uncertainty in, numerical models.

The steam turbine is the simplest and most efficient engine for converting large amounts of heat energy into mechanical work. This article discusses the primary corrosion mechanisms such as corrosion fatigue, stress-corrosion cracking (SCC), pitting, corrosion, and erosion-corrosion, in steam turbines. It illustrates the various causes of the corrosiveness of the steam turbine environments through a Mollier diagram. The article describes the four parts of design disciplines that affect turbine corrosion, namely, mechanical design, heat transfer, flow and thermodynamics, and physical shape. It lists the ways to control the steam and surface chemistry, and design and material improvements to minimize turbine corrosion.

Coextrusion is defined as the simultaneous extrusion of two or more metals to form an integral product that can be carried out using conventional extrusion or drawing equipment at a temperature appropriate to the metal system being formed. This article discusses the applications, billet configurations, and metal flow modes of coextrusion. It presents the analytical studies of coextrusion: deformation energy methods, lower-bound (slab) analyses, upper-bound analyses, and finite-element analyses. These studies are used to identify the regime of material properties and process variables for which sound extrusions can be obtained. The article concludes with a discussion on the state-of-the-art of coextrusion that assists in developing process models, which accurately describe both the macroscopic and microscopic aspects of a process.

Induction hardening of geared parts used in aeronautic and aerospace industry is an important technology because of its one-piece flow, repeatability, energy efficiency, and tighter control of surface distortion than conventional carburizing. This article describes the requirements and characteristics of induction hardening of transmission parts, such as bearings, shafts, and different types of gears, including bevel gears, spur wheel gears, helical gears, and splines. It provides information on process monitoring and the economic aspects of induction hardening.

This article is a comprehensive collection of fluid dynamic equations for properties of fluids, fluid statics, fluid motion, dimensional analysis, and boundary layer flow. It presents equations for analyzing problems in fluid mechanics, continuity equation, momentum equation, and energy equation for solving various problems related to fluid dynamics.

Life-cycle engineering is a part-, system-, or process-related tool for the investigation of environmental parameters based on technical and economic measures. This article focuses on life-cycle engineering as a method for evaluating impacts. It describes the four steps of life-cycle analysis, namely, goal definition and scoping, inventory analysis, impact assessment and interpretation, and improvement analysis. The article discusses the applications of life-cycle analysis results and presents a case history of life-cycle analysis of an automobile fender.