Engineering objects

It is quickly evident, however, that it is necessary to blend theory with experiment to achieve the engineering objectives of predicting fluid-particle flows. Fortunately, there are several semi-empirical techniques available to do so (see Di Felice, 1995 for a review). Firstly, however, it is useful to define some more terms that will be used frequently. 

Chapter 2 zooms in on the possible development and use of tiny engines. Objects in the familiar world obey Newton s laws, at least approximately, but on the atomic or molecular scale, Newton s laws do not apply, and advanced concepts such as quantum mechanics take hold. Gravity is a prominent force in most people s experience—any... 

The engineering objectives of die design are to achieve the desired shape within set limits of dimensional uniformity and at the highest possible production rate. This chapter discusses both objectives, but the question of die-formed product uniformity deserves immediate amplification. To understand the problem, we must distinguish between two types of die-formed product nonuniformity (a) nonuniformity of product in the machine direction, direction z [Fig. 12.2(a)], and (b) nonuniformity of product in the cross-machine direction, direction x [Fig. 12.2(b)]. These dimensional nonuniformities generally originate from entirely different sources. The main source of the former is the variation... 

Simulators. Now that substantial progress has been made in describing the formation, flow, and collapse of lamellae in single capillaries, the construction of detailed mechanistic descriptions of flow in porous media has begun. The ultimate engineering objective of... 

It is necessary to develop an appropriate methodology to harness the potential of CFD tools for engineering analysis and design despite some of the limitations. Computational flow modeling (CFM) includes such overall methodology and all the other activities required to use CFD to achieve the engineering objectives. 

Knowledge of underlying physics and its mathematical representation (Chapters 2 to 5), of numerical methods to solve such mathematical representations (Chapters 6 and 7) and of computational tools to implement these numerical methods (this chapter), equip the reader to harness the potential of computational flow modeling for reactor engineering. It is essential to develop an appropriate modeling approach to suit the reactor-engineering objectives at hand. Development of such approaches is discussed in Chapter 9 with the help of practical examples. 

Adequate mathematical representation of any complex physical process may require many different mathematical models, perhaps a continuum of models, each having different capabilities, appropriate to its specific objectives. Reactor engineers must recognize the possibility of employing a hierarchy of models to develop the necessary understanding and to obtain the required information to achieve complex reactor engineering objectives. Perhaps an analogy with the variety of vehicles... 

In 1927, Harley Earl started the Art and Color Section at General Motors Company. Henry Ford had the vision to realize the potential for car ownership and in the early part of the century ownership of a Model T Ford has enough to confer a high level of status on these customers. Harly Earl went beyond this, he realized that once car ownership was more universal, Americans would want more than reliability and low price. He transformed the automobile from an engineered object to a stylish artifact. This was a dramatic conceptual shift that has never been overturned. He went beyond the rational needs of consumers to a deeper desire and turned the car from a utility object into a realizable dream. Harley Earl had a talent for visualizing dramatic car bodies. He created a car for Fatty Arbuckle and one for Tom Mix that even came with a saddle. 

We have emphasized that the modelling and the associated rock mass characterization should be determined by the rock engineering objective. This means that different types of information will be required for THMC modelling for the different types of application, as illustrated by the themes of this conference and the associated papers. However, site investigation has limited methods of approach, e.g. surface outcrop studies, borehole and borehole core measurements, and geophysics, which means that we will not have as much information as we would like and concessions have to be made on both the site investigation and modelling sides. 

There are two basic strategies nonengineered (subjective) standards ( did take times) and engineered (objective) standards ( should take times). The techniques to use depend upon the cost of obtaining the information and the benefits of using the information. 

One of the desirable end-goals of materials science research is the development of multifunctional materials. These materials are defined as compositions that bring more than one property enhancement to a particular application, thus allowing the material to replace more than one other material in an engineered object, or to replace entire classes of materials which alone, are only capable of addressing one end-use need l-4. ... 

Engineering design is a description of a future engineering object, or a system, and... 

A design concept is an abstract part of an engineering design describing a future engineering object, or system, in terms of symbolic attributes. In computational terms it is a sequence of symbolic attributes and a feasible combination of attributes and their values. 

Specifies the desired features of the future engineering object, or system, including features of its behavior... 

Engineering designing is a process beginning when a need for a new, or modified, engineering object, or a system, is realized and it ends when its final feasible product, an engineering design, or a class of designs, is developed. 

Considering, that the laser technology offers new, efficient possibilities for laying out and checking engineering objects,... 

The virtual world for engineering (Figure 1-1) is constituted of interrelated descriptions of engineering objects as parts, assemblies, kinematics, analysis results, manufacturing processes, production... 

Construction of a virtual world in the course of engineering activities starts from ideas about the system to be modeled and the engineering objects to be included in it. Typically, objects and their structures are defined. The basic approach to construction may be... 

Figure 1-3 Shape based description of engineering objects.

One of the exceptions to shape based engineering objects is an electronic system where active and passive circuit elements are connected by routes but not in a dimensioned space. However, this model of an electronic system is completed with shape models of printed circuit board arrangements and programming of automatic assembly and inspection equipment. At automatic assembly, circuit elements R31, R33, and C33 should be positioned relative to the printed circuit board (Figure 1-4). At automatic inspection, a camera image of the ready assembled printed circuit board is compared with a master image to reveal parts omitted during assembly. 

Figure 1-5 outlines the description of a mechanical part in a virtual world. A virtual space with dimensions of the real space accommodates objects. The object in this example is a part, one of the product related engineering objects. Shape, position, material, surface properties, outside relationships, and behavior of the object are described. Outside relationships include connections to other parts such as contact of surfaces, possibilities of movements relative to other parts such as linear movement along a sUde, and restraints such as a pin. Behaviors of a part are defined by stress. 

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