Simulated Result and Verification

The object of simulation is the adsorption of methylene chloride vapor in air on an activated carbon column, and the simulated results were compared with published experimental data [13]. The details of adsorption column and adsorbent particle properties are given in Table 6.1 

Since the adsorption process is unsteady, a convenient method of solution is to dividing the process time into a large number of time intervals At for stepwise computation. The At in present case is set to be 1 min, which is about 1/140 of the total adsorption time. 

The simulated results and comparison with experimental data are given below. 

Concentration profile along the column at different times 

In the adsorption column, the adsorption is taken place only in certain part of column height as represented by the red bracket shown in Fig. 6.1. The parabolic form of concentration distribution is obvious due to the wall effect. 

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Simulated Results and Verification (I) Separation of ii-Heptane and Methylcyclohexane... 

Simulated Results and Verification (II) Stripping of Toluene from Dilute Water Solution... 

Simulated Result and Verification Separation of Methylcyclohexane and n-Heptane... 

A dramatic example of this type of error was discussed by Donigian, (6j at the Pellston workshop based on the Iowa study described earlier (8 ) Figure 3 shows the calibration (top figure, 1978 data) and verification (bottom figure, 1978) results. A simulated alachlor concentration value of greater than 0.1 mg/1 occurred on May 27, 1978, (top figure) whereas the observed... 

P 28] A 3-D solid model of the cross-shaped micro mixer is meshed to a sufficiently fine scale with brick elements of 2 pm for the simulations [71]. Simulation results were intended at very short time scales, e.g. in intervals of 50 ps, to verify the mixing patterns at the initial state after application of pressure. The numerical values of the mass fraction are taken to give quantitative measures of the mixing efficiency. The pre-processor fluidics solver and post-processor of ConventorWare were used for the simulations. The software FLUENT 5 was used for verification of these results, since the former software is so far not a widely established tool for fluid dynamic simulation. 

Figure 22. Influence of activity profiles on the temperature profile of a strongly exothermic reaction. A) Catalyst with 66% activity in the front section and 100% activity in the back [37] B) Linear (broken line) and optimal catalyst activity distribution (full line) for limiting the maximum temperature to 370 °C (simulation result) C) Experimental verification of B [38].

The existing concept of mobility control is that the displacing fluid mobility should be equal to or less than the (minimum) total mobility of displaced multiphase fluids. This chapter first uses a simulation approach to demonstrate that the existing concept is invalid the simulation results suggest that the displacing fluid mobility should be related to the displaced oil phase mobility, rather than the total mobility of the displaced fluids. From a stability point of view, a new criterion regarding the mobility control requirement is derived when one fluid displaces two mobile oil and water fluids. The chapter presents numerical verification and analyzes some published experimental data to justify the proposed criterion. 

Two methods for verifying the validity of a received watermark message were proposed in Section 3. Here, simulation results for both methods arc compared. Fig. 6 shows the measured false positive and false negative probability for a verification bit vector f of length Lf = 15. The watermark message u was embedded with a rate 1/3 CC with memory length v = 4. 

With increasing model complexity and multiple interacting processes, complete and unambiguous verification and validation may be impossible due to the unavoidable non-uniqueness of simulation results. However, the lack of general validation does not detract from the value of the model, which is, above all, a tool to give insight into complex processes. 

This section addresses formal analysis of the simulated traces. Section 6.1 addresses specification of (global) dynamic properties, Sect. 6.2 address specification of interlevel relations between dynamic properties at different aggregation levels, and Sect. 6.3 discusses some results of verification of properties against empirical and simulated traces. 

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