Design engineering

Design is a very important engineering activity. It involves meeting some need by applying the laws of physics and chemistry, using mathematics, and the computer where appropriate. Steps in the design process involve some or all of the following  

Comparing possible approaches and selecting the one which appears to be most promising. 

Performing detailed design based on the selected approach. 

Specifying shapes, materials, tolerances, standard parts, methods of manufacture, and methods of testing and evaluation. 

Redesigning to take care ofproblems uncovered, optimizing. 

Engineering design is a product of an activity called the engineering designing process, which is discussed in Section 4.3. In general, it may be described thus  

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

It contains all the organized information (a body of knowledge) necessary and sufficient to build, maintain, and eventually to demolish this object or system to recover materials. 

It has two components, including a design concept and a detailed design. 

A design concept represents the qualitative or abstract part of an engineering design. It can be defined thus  

A membrane system can be designed by empirical or semiempirical approaches and computer-simulation models. The former can be found in the literature such as Geankoplis s manuscript (26) the later is illustrated by Judd and Jefferson (3). A frequently used design tool based on a semiempirical approach is given below. 

Mass transfer of substances in a membrane unit can be considered as steady-state diffusion, which can be described by the following equations (6,12,40,49). A conceptual illustration of RO is given in Fig. 21. Noted that 1 and 2 represent feed and permeate (product) sides, respectively. 

Water permeability constant (A ) is a function of the membrane material such as water membrane permeability and membrane thickness. The presence of salt, however, is less important for the constant. For CA membranes, A typically ranges from 1 x 10 to 5 X 10 kg water/s-m -atm. Salt permeability constant depends on the types of salts in the solution. For CA membranes, A values range from 1 x 10 to 6.0 x 10 m/s. The values are 4 X lO m/s for NaCl, 2.2 x 10 m/s for MgClj, 2.4 x 10 m/s for CaCl2, 6.0 X 10 m/s for KCl, and 4 x lO m/s for Na2S04, respectively. 

The solution volumetric flow rate in the feed side is approximately equal to that in the permeate side. Therefore, we have 

If the salt concentration in permeate (product) (C2) is low, its osmotic pressure (112) is normally ignored and the concentration of water in permeate (product) is approximately the pure water density that is a function of temperature (Table 5). 

A er FEED, if owner decides to go ahead with the project, the next phase is detailed engineering design work. There are many tasks for process engineer to do. Some important tasks are described below. 

Vtock vahw on lerti bridte b 3 , on tewt transmitter is 2, and on level gauge 3/4 . Vent and drain block valves are 3/4 lb r art not shown fior clarHy reason. i. Interface liquid level In bool art as follows HIL at i -CT, NIL at S -O , and UL at from boot tangent line. 

Because the last trial gives a close agreement with the LHS value of 203,189 cal, we take the solution to be T i 1,345°C. It is concluded that all of the three methods of calculations provide the same final answer. 

Petroleum engineers are traditionally involved in activities known in the oil industry as the front end of the petroleum fuel cycle (petroleum is either liquid or gaseous hydrocarbons derived from natural deposits—reservoirs—in the earth). These front end activities are namely exploration (locating and proving out the new geological provinces with petroleum reservoirs that may be exploited in the future), and development (the systematic drilling, well completion, and production of economically producible reservoirs). Once the raw petroleum fluids (e.g., crude oil and natural gas) have been produced from the earth, the back end of the fuel cycle takes the produced raw petroleum fluids and refines the.se fluids into useful products. 

Development of new proven petroleum resources are also cost-intensive operations, but generally lack the high risk of nearly total capital loss that exists in exploration 

The development effort is largely a engineering activity requiring a great deal of planning. This planning requires increased interaction of multiple engineering disciplines to assure that the wells are drilled, completed and produced in a safe, efficient and economical manner. 

There are three basic engineering fields of knowledge. These are called the engineering arts and sciences. They are the mechanical arts and sciences, the chemical arts and sciences, and the electrical arts and sciences. Every specific engineering discipline, such as petroleum engineering, utilizes one of the basic engineering fields of knowledge as their scholarly foundation. 

Plastics materials Usage (Tonnes 1984 1985 X 1000) 1986 Price Band  

Linear low density polyethylene (LLDPE) High density polyethylene (HDPE) 210 250 275 A/B (Cg copolymer) A 

Thermosets Phenol-formaldehyde (PF) resins 49 50 49 D-F (Novolak resins) 

PF (moulding grades) 14 14 12 B (Resol solution) D/E (Resol-100% solids) B 

Unsaturated polyester resins (UPR) 50 51 53 C/D (MF moulding powders) A-D (MF impregnation resins and solution) E/F 

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W. C. Davis, "Detonation Phenomena," ia / 2th A.nnual Symposium on Behaniour and Efiliation of Explosives in Engineering Design, University of New Mexico, Albuquerque, 1972. 

Military Pyrotechnics, AMCP 706-185 to 189, Engineering Design Handbook Series, U.S. Army Material Command (AMC), Alexandria, Va., 1974. 

S. A. Moses, "Explosive Components for Aerospace Systems," in Behaviour and Utilisation ofiExplosives in Engineering Design,... 

J. H. McLain, Principles of Explosive Behavior, Engineering Design Handbook, AMC 706-180, AMC, Alexandria, Va., 1972. 

Interior Ballistics of Guns, Engineering Design Handbook, AMCP 706—150, DARCOM, 1965. 

J. D. Griffin and R. E. Skochdopole, ia E. Baer, ed.. Engineering Design for Plastics, Reinhold Publishing Corp., New York, 1964. 

Knock is caused by unwanted chemical reactions in the combustion chamber. These reactions are a function of the specific chemical species which make up the fuel and the environmental conditions to which the fuel is subjected during the compression and power stroke in the engine. Therefore, both the chemical makeup of the fuel and the engine design parameters must be considered when trying to understand knock. 

J. H. Eaupel and E. E. Eisher, Engineering Design, McGraw Hill Book Co., Inc., New York, 1982. 

R. D. McCarty,. Hord, H. M. Roder, S elected Properties of Hydrogen (Engineering Design Data). U.S. Dept, of Commerce, National Bureau of Standards, Washington, D.C., 1981, pp. 6—291. 

R. A. Wadden and P. A. Scheff, Engineering Design for the Control of Workplace Hazards, McGraw-HiU Book Co. Inc., New York, 1987. 

JRMCP 706-133, Engineering Design Handbook, Maintainability Engineering Theory and Practice, U.S. Army Materiel Command, Washington, D.C., 1976. 

K. C. Kapur and L. R. Lamberson, Reliability in Engineering Design, John Wiley Sons, Inc., New York, 1977. 

U. S. Army Materiel Command, Engineering Design Handbooks-Development Guide forReliability, Part 2 Design for Reliability (AMCP 706-196) Part 3 Reliability Prediction (AMCP 706-197) Part 4 Reliability Measurement (AMCP 706-298), National Technical Information Service, Springfield, Va., 1976. 

Hz unit. To accommodate the higher firing temperatures and mass flows, these units employ advanced alloys, coatings, and modified cooling schemes. Many features of these units were derived from aircraft engine designs. 

Minimization of impingement risks focuses on site-specific analyses of potentially vulnerable species and selection of engineering designs which, within acceptable cost limits, keep impingement deaths low. 

Viscosity is an important property of calcium chloride solutions in terms of engineering design and in appHcation of such solutions to flow through porous media. Data and equations for estimating viscosities of calcium chloride solutions over the temperature range of 20—50°C are available (4). For example, at 25°C and in the concentration range from 0.27 to 5.1 molal (2.87—36.1 wt %) CaCl2, the viscosity increases from 0.96 to 5.10 mPa-s (=cP). 

R. J. Wakeman and Fan Deshun, Chemical Engineering Design Research 69(A5), 403 (1991). 

If the product is an engineering service, then the price is determined by the availabiHty, reputation, and price of competitive providers, as well as the uniqueness and scope of the service. Examples iaclude engineering design, technical laboratory services, project management, and constmction. 

The operating air/fuel mixture of the two-stroke engine designs range from 1.3 to 2.0 stoichiometric. This lean mixture plus the characteristic internal exhaust gas recirculation lowers the peak combustion temperatures and results in low NO formation. 

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