Simulation cont

Simple control strategies form an integral part of many of the simulation examples, including RELUY, COOL, DEACT, REFRIG1, REFRIG2, RUN, EXTRA-CTCON, SULFONATION and the special control examples in Sec. 5.7, TEMP-CONT, TWOTANK and CONTUN. 

Sorensen, B. (2003b). Time-simulations of renewable energy plus hydrogen systems. In "Hydrogen Power - Theoretical and Engineering Elutions. Proc. Hypothesis V, Porto Conte 2003" (Marini, M., Spazzafumo, G., eds.), pp. 35-42. Servizi Grafici Editoriali, Padova. 

Walsh J. J., Dieterle D. A., and Meyers M. B. (1988) A simulation analysis of the fate of phytoplankton within the mid-Atlantic Bight. Cont. Shelf Res. 8, 757-787. 

Newland L. W., Chesters G., and Lee G. B. (1969) Degradation of 7-BHC in simulated lake impoundments as affected by aeration. J. Water Pollut. Cont. Fed. 41(5), R174-R188. 

Duan ZH, Xiao HL, Dong ZB (2002) Estimates of total CO2 output from desertified sandy land in China. Atmos Environ 35(34) 5915-5921 Fang GH, Kwok YK, Yu KJ, Zhu YH (1999) Numerical simulation of principal tidal constituents in the South China Sea, Gulf of Tonkin and Gulf of Thailand. Cont Shelf Res 19(7) 845-869... 

In the HYSYS.Plant simulator, this is accomplished by the Adjust operation, in CHEM-CAD by the CONT subroutine, and in PRO/II by the CONTROLLER subroutine. In ASPEN PLUS, the equivalent is accomplished with so-called design specifications. The latter terminology is intended to draw a distinction between simulation calculations, where the equipment parameters and feed stream variables are specified, and design calculations, where the desired properties of the product stream (e.g., temperature, composition, flow rate) are specified and the equipment parameters (area, reflux ratio, etc.) and feed stream variables are calculated. In HYSYS.Plant, the Adjust operation is used to adjust the equipment parameters and some feed stream variables to meet the specifications of the stream variables. Furthermore, the Set object is used to adjust the value of an attribute of a stream in proportion to that of another stream. 

For assistance in the use of the Adjust and Set objects, the reader is referred to the module HYSYS -> Principles of Flowsheet Simulation Getting Started in HYSYS -> Convergence of Simulation on the multimedia CD-ROM that accompanies this text. As was discussed in the subsection on bidirectional information flow, for all of its subroutines, HYSYS.Plant provides a bidirectional information flow, that is, when product stream variables are specified, the subroutines calculate most of the unknown inlet-stream variables. In CHEMCAD, a control unit, with one inlet stream and one outlet stream (which may be identical to the inlet stream), is placed into the simulation flowsheet using the CONT subroutine. The parameters of the control unit are specified so as to achieve the desired value of a stream variable (or an expression involving stream variables) or an equipment parameter (or an expression involving equipment parameters) by manipulating an equipment parameter or a stream variable. This is the feed-backward mode, which requires that the control unit be placed downstream of the units being simulated. The CONT subroutine also has afeed-forward mode. 

Fig. 41. (cont.) NHj /Na ferrierites. (c) Isotropic (FI) projections of the LaI 5Q (MQ) MAS NMR spectra together with simulations. Compositions are mentioned in figures, where the first number denotes the Si/Al ratio and second one the Na content [98S1]. 

Arattano M, Franzi L, March L (2006) Influence of rheology on debris flow simulation. Nat Hazards Earth Syst Sci 6 519-528 Arattano M, Conte R, Franzi L, Giordan D, Lazzari A, Luino F (2010) Risk management on an alluvial fan a case study of the 2(X)8 debris-flow event at Villar Pellice (Piedmont, N-W Italy). Nat Hazards Earth Syst Sci 10 999-1008 Arattano M, March L, Cavalli M (2012) Analysis of debris flow recordings in an instrumented basin confirmations and new findings. Nat Hazards Earth Syst Sci 12 679-686... 

Boore DM (2009) Comparing stochastic point-source and finite-source ground-motion simulations SMSIM and EXSIM. Bull Seismol Soc Am 99 3202-3216 Conte JP, Peng BF (1997) Fully nonstationary analytical earthquake ground-motion model. J Eng Mech ASCE 12 15-24... 

Worldwide, there is a large number of published works. There are several research areas in the general context of underwater robotics, such as modeling the interaction between fluid and stmcture (Ridao Batlle, 2001), modeling of the actuators (Blanke, et al., 1991), control techniques for the vehicle (Antonelli, et al., 1991), simulation environments (Conte Serrani, 1991), and vehicle design (Miller, 1999). 

Conte, G., Serrani, A. (1991). Modeling and simulation of underwater vehicles. In Proceedings of the IEEE International Symposium on Computer-Aided Control System Design, (pp. 62-67). Dearborn, Ml IEEE Press. 

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