Numerical simulation of radiating flows
Karaismail, Ertan; Selçuk, Nevin; Department of Chemical Engineering (2005)
Predictive accuracy of the previously developed coupled code for the solution of the time-dependent Navier-Stokes equations in conjunction with the radiative transfer equation was first assessed by applying it to the prediction of thermally radiating, hydrodynamically developed laminar pipe flow for which the numerical solution had been reported in the literature. The effect of radiation on flow and temperature fields was demonstrated for different values of conduction to radiation ratio. It was found that ...
Model Predictive control(MPC)performance for controlling reaction systems
Aşar, Işık; Özgen, Canan; Department of Chemical Engineering (2004)
In this study, the performance of the Model Predictive Controller (MPC) algorithm is investigated in two different reaction systems. The first case is a saponification reaction system where ethyl acetate reacts with sodium hydroxide to produce sodium acetate and ethanol in a CSTR. In the reactor, temperature and sodium acetate concentration are controlled by manipulating the flow rates of ethyl acetate and cooling water. The model of the reactor is developed considering first principal models. The experimen...
Mathematical modeling of nox emissions in bubbling fluidized bed combustors
Afacan, M. Onur; Selçuk, Nevin; Department of Chemical Engineering (2005)
A comprehensive model, previously developed and tested for prediction of behavior of continuous fluidized bed combustors is extended to incorporate NOx formation and reduction reactions and applied to the simulation of METU 0.3 MWt Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) burning lignites with high volatile matter in their own ashes. The predictive accuracy of the model was assessed by comparing its predictions with measurements taken previously on the same rig. Favorable comparisons are obtaine...
Numerical simulation of laminar reaction flows
Tarhan, Tanıl; Selçuk, Nevin; Department of Chemical Engineering (2004)
Novel sequential and parallel computational fluid dynamic (CFD) codes based on method of lines (MOL) approach were developed for the numerical simulation of multi-component reacting flows using detailed transport and thermodynamic models. Both codes were applied to the prediction of a confined axisymmetric laminar co-flowing methane-air diffusion flame for which experimental data were available in the literature. Flame-sheet model for infinite-rate chemistry and one-, two-, and five- and ten-step reduced fi...
Determination of degree of mixing in solid rocket propellants
Yeşilırmak, Yener; Yılmazer, Ülkü; Department of Chemical Engineering (2006)
Composite propellants are mainly composed of: crystalline oxidizer, metallic fuel, and polymeric binder. Additives, such as plasticizers, catalysts, bonding agents and curing agents may also be incorporated to propellant compositions in small amounts. These ingredients should be mixed rigorously in order to obtain a uniform microstructure throughout the cast propellant profile. The quality of the propellant mixture has to be determined quantitatively to improve the product quality and to reduce costs. In th...
Citation Formats
I. TOSUN and I. AKSAHIN, “PREDICT HEATING AND COOLING TIMES ACCURATELY,” CHEMICAL ENGINEERING, pp. 183–184, 1993, Accessed: 00, 2020. [Online]. Available: