Simulation language

GPSS/PC, developed by Minuteman Software (Stow, Mass.) for IBM-compatible personal computers, is based on the popular discrete simulation language GPSS (general purpose simulation system). Reference 14 provides more details. 

All the above changes are easily implementable in dynamic simulations, using ISIM and other digital simulation languages. The forms of response obtained differ in form, depending upon the system characteristics and can be demonstrated in the various ISIM simulation examples. The response characteristics of real systems are, however, more complex. In order to be able to explain such phenomena, it is necessary to first examine the responses of simple systems, using the concept of the simple, step-change disturbance. 

It is thus very important that the output of any simulation is checked, using other integration methods. Most simulation languages allow a choice of integration routine which can be made best on the basis of experience. It is... 

The main process variables in differential contacting devices vary continuously with respect to distance. Dynamic simulations therefore involve variations with respect to both time and position. Thus two independent variables, time and position, are now involved. Although the basic principles remain the same, the mathematical formulation, for the dynamic system, now results in the form of partial differential equations. As most digital simulation languages permit the use of only one independent variable, the second independent variable, either time or distance is normally eliminated by the use of a finite-differencing procedure. In this chapter, the approach is based very largely on that of Franks (1967), and the distance coordinate is treated by finite differencing. 

Axial and radial dispersion or non-ideal flow in tubular reactors is usually characterised by analogy to molecular diffusion, in which the molecular diffusivity is replaced by eddy dispersion coefficients, characterising both radial and longitudinal dispersion effects. In this text, however, the discussion will be limited to that of tubular reactors with axial dispersion only. Otherwise the model equations become too complicated and beyond the capability of a simple digital simulation language. 

As in Example BSTILL, a column containing four theoretical plates and reboiler is assumed, together with constant volume conditions in the reflux drum. The liquid behaviour is, however, non-ideal for this water-methanol system. The objective of this example is to show the need for iterative calculations required for bubble point calculations in non-ideal distillation systems, and how this can be achieved with the use of simulation languages. 

The included diskette contains the ISIM simulation language as well as simulation examples. It can be run on all DOS-PC s. 

The ISIM software is made available only for the purposes described in this book, and its features are restricted to the.se examples. An advanced simulation language, ESL, is highly recommended and is also available. Users wishing to purchase the latest version of the ISIM or ESL should contact ISIM International Simulation directly. User manuals for ISIM may also be purchased for 40 from ISIM International Simulation. 

The textbook is the first of its kind to include a diskette with a commercial simulation language. The diskette can be run on any DOS personal computer. 

RS Thomas, WE Lytle, TJ Keefe, AA Constan, RSH Yang. Incorporating Monte Carlo simulation into physiologically based pharmacokinetic models using advanced continuous simulation language (ACSL) A computational method. Fundam Appl Toxicol 31 19-28, 1996. 

Most simulation languages include a standard time delay function, which is pre-programmed into the language structure. This facility is also available in MADONNA and is implemented in several of the simulation examples. 

In practice, however, these simulation languages have limited utility. In their push for generality, they usually have become inefficient. The computer execution time for a realistic engineering problem when run on one of these simu-... 

Eqs. (2.14), (2.30), and (2.31) with Eq. (2.9) can be solved simultaneously without simplification. Since the analytical solution of the preceding simultaneous differential equations are not possible, we need to solve them numerically by using a computer. Among many software packages that solve simultaneous differential equations, Advanced Continuous Simulation Language (ACSL, 1975) is very powerful and easy to use. 

For more details of this simulation language, please refer to the ACSL User Guide (ACSL, 1975). 

Eq. (3.34) cannot be solved analytically because it is a nonlinear differential equation. It can be solved by various numerical techniques. Again Advanced Continuous Simulation Language (ACSL, 1975) can be used to solve the problem. Since Eq. (3. 34) is a second-order differential equation, it has to be changed to two simultaneous first-order differential equations to be solved by ACSL as... 

Advanced Continuous Simulation Language User Guide Reference Manual. Concord, MA Mitchell and Gauthier, Assoc., Inc., 1975. 

You can solve Eqs. (6.23) and (6.24) to calculate the change of Cx and Cs with respect to time, which involves the solution of a nonlinear equation. Alternatively, the Advanced Continuous Simulation Language (ACSL, 1975) can be used to solve Eqs. (6.22) and (6.23). 

Numerical integration of the preceding equation by using Advanced Continuous Simulation Language (ACSL) or other method yields... 

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