Calculation Engine

The calculation engine is the heart of the property system. The specific contents of the engine are determined by the industries the system is designed to serve. In general, the engine should contain the following  

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In addition to phase change and pyrolysis, mixing between fuel and oxidizer by turbulent motion and molecular diffusion is required to sustain continuous combustion. Turbulence and chemistry interaction is a key issue in virtually all practical combustion processes. The modeling and computational issues involved in these aspects have been covered well in the literature [15, 20-22]. An important factor in the selection of sub-models is computational tractability, which means that the differential or other equations needed to describe a submodel should not be so computationally intensive as to preclude their practical application in three-dimensional Navier-Stokes calculations. In virtually all practical flow field calculations, engineering approximations are required to make the computation tractable. 

It should be said that the phase plane of itself cannot be guaranteed to give the whole behavior, for, in computing phase planes, one cannot be sure that one has started in the regions of attraction of all the steady or periodic solutions present. In 1956, the theory that is needed for this to be done systematically was 20 years into the future, and the calculating engines were just beginning to become really powerful. Fortran had not been invented, and each cell had to be addressed by its number, in octal 7... 

At any point during the test, calculate engineering stress (oeng) and engineering strain (eeng) from the force/deformation data set or plot ... 

Using the symbolic calculation engine available in Matlab ,2 we obtained the following description of the intermediate dynamics of the reactor-condenser process ... 

Programmable interfaces, whether proprietary or public, allow the calculation engine to be used by other engineering programs. The interface must include ... 

In order to maximize the value of the applied thermodynamics system throughout the enterprise, it must be accessible to all process engineers and chemists who require accurate thermophysical property calculations in their daily work. Web applications, which do not require installation of the calculation engine on the user s computer, facilitate ea.sy access to the system. Web applications can be designed to provide pure component data such as normal boiling point and critical properties. They can also provide access to the most frequently carried out calculations, such as phase equilibrium calculations, tabulation, and plotting of pure component properties as a function of temperature and pressure, and mixture property calculations. 

The next two sections of this chapter treat the technical history of computational chemistry, namely the development of the hardware, concepts, and methods used in the field. We discuss first the chemists earliest uses of the computer as a research tool in the 1950s. The first stored program electronic digital computers became available in the early 1950s in chemistry, as in other branches of science, these devices were initially deployed as calculating engines. Next we deal with the expansion of the field of computational chemistry during... 

Hysys.Operator Training start-up, shutdown or emergency conditions, consisting of an instructor station with DCS interface, and combined with Hysys.Plant as calculation engine. 

Before the computer age, the friction factor plot and the convenience plots made from it were the only means that engineers had of solving fluid friction problems in pipes. For an occasional such calculation or a problem outside the normal range of the engineer s experience, they are probably still the best way. However, for routine pipe friction calculations, engineers use computers. To do so, they need equations equivalent to the friction factor plot. 

In the field bus control system, sensor measurement, compensation calculation, engineering quantity processing and control functions in the field of equipment complete, relying on the field devices to complete the basic functions of automatic control, operation state and can at any time... 

Standard Template Library (STL) is a set of C++ classes standardized across a number of C++ compilers for different platforms. It is selected to build all analysis engines which require tremendous scientific calculations. Engine building in STL requires individual building or compilation for each platform that it supports. User can get pre-defined packages based on the platform they are using. 

We currently use a generic mechanism to deploy such standardized descriptor calculations, QS AR-models, and other services that have been implemented in different workflow tools to a number of different front-ends. This ensures that the end user sees identical descriptor values regardless of the front-end. The mechanism works completely asynchronously and uses a database as intermediate communication infrastructure. The database layer ensures that a request is stored persistently until it is processed—it thus automatically provides a buffering mechanism for large requests or computationally expensive calculations and guarantees that no requests are lost even if one of the calculation engines should be unavailable. 

Heat Transfer Calculations. Engineers are accustomed to dealing with rate coefficients and temperature differentials in their heat-transfer calculations. The heat... 

Table 11.2 Experimental and calculated engineering constants for T300/5208 laminates...

Variables and Units handle real, imaginary, and complex numbers with or without associated units. A high-performance calculation engine provides speed and sophisticated memory management to help find solutions faster. 

MATLAB Contains the EPRLL line shape calculation engine (a dynamic load library, or DLL file) that is callable from MATLAB for use in customized least-squares optimization. 

The databanks can be regarded as the fuel for the PPDS-2 calculation engine. The most important bank in any bank set is the PC-BANK. It provides a set of physical constants and regression coefficients for the temperature-dependent properties. The PPDS SYSTEM bank has information for some 1500 pure components, in a form which... 

Thirdly, due to its efficient calculation engine, initial LoC estimates for entire sites can be calculated in a matter of minutes which makes it very easy to minimize the LoC frequencies in process plants in the future. 

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