Parameter sensitivity studies

Study/values Pi (l/min) (main reaction) Pi 0/tnin) (coking) Ps (i/min) (side reaction) 3f () (final activity) 

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Numerical simulations are designed to solve, for the material body in question, the system of equations expressing the fundamental laws of physics to which the dynamic response of the body must conform. The detail provided by such first-principles solutions can often be used to develop simplified methods for predicting the outcome of physical processes. These simplified analytic techniques have the virtue of calculational efficiency and are, therefore, preferable to numerical simulations for parameter sensitivity studies. Typically, rather restrictive assumptions are made on the bounds of material response in order to simplify the problem and make it tractable to analytic methods of solution. Thus, analytic methods lack the generality of numerical simulations and care must be taken to apply them only to problems where the assumptions on which they are based will be valid. 

We have been discussing a class of penetration problems that are accurately modeled by two-dimensional calculations. There are many three-dimensional problems, however, that can be well approximated by two-dimensional analyses, and the greatly reduced computer memory and time requirements for such calculations make them attractive alternatives for scoping studies, or for parameter sensitivity studies. Although good quantitative predictions may not be obtained with such approximations, the calculations can be expected to reveal trends and qualitative results that will carry over to the full three-dimensional problem. 

Murgai and Emmons [451] and Emmons and Ying [169] describe integral plume models, which are calibrated with experimental data. Satoh and Yang [559] used the UND-S AFE code with associated 3d, compressible, buoyant, and constant turbulent viscosity specifications. Ten cases were considered which included validation exercises and parameter sensitivity studies. 

F9-Z. "What if.. " problem. These problems build in the Living Example Problems in this chapter. By this point in the point the studerrt is in a position to carry out in-depth and meaningful parameter sensitivity studies. If there is only time to assign one or two parts of this problem I would choose part (a) and then either (d) or (e>. However, one could rotate the assignments of (a) through (e) from year to year. 

Considering the need for multiple problem solutions for case studies involving autoregulatory effects as well as parameter sensitivity studies and the analysis of pathological phenomena, we decided to simplify the mathematics by using lumped-distributed parameter approximations. 

The model is an extension of the work of Froment and Bischoff [5,6], in which the reaction rate constants depend on the carbon content on the catalyst. The model assumes that coke is formed from an adsorbed reaction intermediate, and that the reaction to form coke is much slower than the reaction to form product. The model developed matches the experimental breakthrough curves for 111 TCA for temperatures above 523 °C. The model also accurately describes the measured coke profile in the reactor. A parameter sensitivity study showed that the coking coefficients, which relate the rate constants to the coke concentration, have the greatest effect on the predicted breakthrough curves and coke profiles. 

A parameter sensitivity study was carried out at 523K to fiirther understand the effect of the four parameters in the model. Each parameter was varied +/- 5% from baseline. The model failed to converge when a2/a3 was greater than the baseline value and ai was less than the baseline value, for all combinations of k and that were evaluated. The model... 

Approaches synergistically combining both top-down and bottom-up modeling viewpoints should be further developed. Macroscopic equations in top-down models should be written in terms of parameters with values calculated from lower-scale simulations. Implementation of such parameters into the macroscopic model should be done including empirical errors. Methodological evaluation of these parameters should be done systematically for instance, coarse models should be developed first, with parameter sensitivity studies guiding further calculations at lower scales. 

Parameter sensitivity analysis of dampers is adequate because it can reveal the correlation between dampers and structural responses, therefore is conducive to the damper optimization. Various damping coefficients C are employed to conduct the parameter sensitivity study of dampers. The value of C ranges from 1 x 10 to 20x 10 kN-s/m, and a is 1.0, according to the linear damper. 

Solsvik J, Jakobsen HA (2011) A numerical study of a two property catalyst/sorbent pellet design for the sorption-enhanced steam-methane reforming process modeling complexity and parameter sensitivity study. Chem Eng J 178 407-422... 

Heat Balances - Design and Off-Design System Performance, Parameter Sensitivity Studies. 5... 

Preliminary Design Heat Balances and Parameter Sensitivity Studies.6... 

This section describes the results of system heat balance studies and parameter sensitivity studies that were performed for the Prometheus Space Nuclear Power Plant (SNPP). These evaluations were performed to establish the range of plant operating parameters needed to satisfy the requirements described in Section 1. The results of these studies are used to establish SNPP component sizing and operating conditions, enable comparison of candidate system architectures, and initiate trade studies. A few key observations regarding these preliminary heat balances and parameter sensitivity studies are ... 

As discussed in Section 6.3.4, the four Brayton system is able to produce only -98% of the required 185 kWe given the assumed piping arrangement and system parameters. Parameter sensitivity studies (Section 6.3.6) indicate that the four Brayton system remains a viable plant configuration as very minor changes to the baseline assumptions utilized here result in a plant output of 185 kWe. 

The plant parameter sensitivity studies described in this section demonstrate that significant improvements in system performance can be realized with advances in a few key technology areas. Relatively minor improvements in heat pipe capability (heat flux vs. operating temperature and service life) and Brayton turbomachinery performance (turbine and compressor efficiency) were found to provide significant system benefits. Piping system and component pressure losses were also found to have a significant impact on overall plant efficiency. 

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