In this study, a robust H_2/H_∞ multi-objective state-feedback controller and tracking design are presented for a mobile TWO-wheeled inverted pendulum (MTWIP). The proposed control has to track the desired angular velocity while keeping the mobile TWO-wheeled inverted pendulum balanced. First, error of output states are added to the dynamic of system for better tracking control. And uncertainties of parameters are defined by affine parameters. Next, Takagi-Sugeno (T-S) fuzzy MODEL is used for estimating the uncertainty of nonlinear MODEL parameters. Robust H_2/H_∞ controller is designed and analyzed for each local linear subsystem of mobile TWO-wheeled inverted pendulum by using a linear matrix inequalities method. To sum up, in order to calculate the whole dynamic of system from each local linear subsystem, weight average defuzzifer method is used and the total controller is designed and analyzed according to parallel distribute compensation. The simulation indicate that the proposed scheme has high accuracy, robustness, good tracking, fast transient responses and lower control effort for a mobile TWO-wheeled inverted pendulum despite the uncertainties and external disturbance.

Numerical MODELing of compressible TWO-phase flow is a challenging and important subject in practical cases and research problems. In these problems, mutual effect of shock wave interaction creates a discontinuity in the FLUID properties and interface of TWO FLUIDs as a second discontinuity lead to some difficulties in the numerical approximations and estimating an accurate interface during the hydro-dynamical capturing process. The main objective of this research is accurate capturing of the interface and numerical study of shock wave during gas-gas and gas-liquid interface of TWO-phase flows. For these purposes , HLLC Riemann solver and Godunov numerical method was used for a hyperbolic TWO-pressure TWO-FLUID MODEL where programming was conducted in TWO-space dimensional with the second order accuracy. Various one and TWO-dimensional problems were simulated such as compression and expansion shock tubes, shock wave interaction with R22/air bubble, underwater explosion and hypersonic shock with M=6 interaction with a cylindrical water column. The numerical results obtained from this attempt exhibit very good agreement with the experimental results, as well as the previous numerical results presented by the other researchers based on the other numerical methods.

One of the most effective drying mechanisms used today is FLUIDized bed drying. The enhanded drying rate in this method is contributed to the FLUIDization of particles, resulting in an increased contact area and hence an increase in heat and mass transfer rates. The MODEL which is basd on a TWO-FLUID MODEL, provides the velocity, temperature profiles of phases, moisture content and the voidage distribution. One-dimensional finite volume scheme is used for the proposed MODEL and the Simpler Algorithm is utilized for the hydrodynamic of the flow field. The verification of the theoretical results was done by the use of an experimental set up. The results indicate a good agreement between the mathematical MODEL and the experiment.

In this paper, a numerical study was conducted to study the effect of the liquid phase compressibility variability in the TWO-FLUID single-pressure MODEL. The TWO-FLUID MODEL is solved by a class of conservative shock-capturing method. The TWO-FLUID MODEL is solved once with the assumption that the density of the liquid phase and one is assumed, assuming that the liquid phase density is varied. In order to examine the compressibility effect, the liquid phase density of the three sample problems was used with different pressure conditions. The results show that, under atmospheric conditions, variations in the density of the liquid phase can be neglected and have no effect on the accuracy of the results of the TWO-FLUID single-pressure MODEL. In the case of extreme pressure gradients, the variability of the liquid phase density in a TWO-FLUID single-pressure MODEL causes deviation of numerical results. Therefore, in the case of extreme pressure gradients, TWO-FLUID single-pressure MODEL is a more accurate MODEL assuming that the liquid phase density is constant.

This paper presents a new and accurate methodology for transient and dynamic behavior of slug hydrodynamic instability MODELing in horizontal and inclined channels. The base of this methodology is on numerical solution of hyperbolic TWO FLUID MODEL equations by means of a class of high resolution shock capturing methods. The privilege of this method is that it can MODEL and predict initiation and growth of slug in stratified flow automatically and directly by solving the flow field differential equations. The well-defined test case considered for the verification and validation of the results is the Ransom Water Faucet case. The results obtained for slug flow MODELing in horizontal duct were compared with TWO sets of experimental results. The good agreement of the present MODELing results with the experimental results of own and other investigators and also grid independency study show the MODEL is capable of slug tracking and slug capturing and the numerical method which is used here can predict with high enough accuracy.

A TWO FLUID MODEL (TFM) was used to study gas-solid heat transfer in a riser with different inclination angles. A TWO dimensional pipe with 5. 8 cm internal diameter and 5 meter length was chosen. Effect of bed angle and solid particles feed rate were studied on the heat transfer behavior of gas and solid particles. Obtained results from simulation are compared with the experimental data in the relevant literature. Heat transfer behavior of phases is different in an inclined pipe in comparison with vertical and horizontal pipes. It is found that higher air-solid Nusselt number, air temperature difference and particle temperature difference take place at the pipe with inclination angle equal to 45 degrees. Loading ratio enhancement increases gas temperature differences. At lower and higher loading ratio, particles temperature differences decreases and increases respectively with loading ratio enhancement.

In this study, gas evolution in a vertical electrochemical cell is investigated numerically with a modified TWO-FLUID MODEL. The mathematical MODEL involves solution of separate transport equation for the gas and liquid phases with an allowance to inter-phase transfer of mass and momentum. The governing equations are discreted via the finite volume technique and then are solved by the SIMPLE algorithm in both the natural and forced convection states. In order to increase the accuracy of calculations, the power-law scheme is employed to approximate the convection-diffusion terms. Void fraction distribution of chlorine gas and velocity of both the gas and liquid phases are calculated. Also the effect of current density, electrolyte flow rate and space between the electrodes on the gas release are investigated. To verify this MODEL, numerical simulations of a bubble-driven flow caused by the bottom injection of gas into a liquid bath is conducted. Comparisons between the predictions and the literature numerical datas illustrate that the predicted results satisfactorily agree with data available in the literature for both the liquid and gas phases.

The present paper is a study on dispersion of reactive solute in an oscillatory flow of a TWO-FLUID, three-layer Casson-Newtonian continuum using Aris-Barton’ s approach. A TWO-FLUID MODEL of blood flow has been considered, the FLUID in the central region is taken to be a Casson FLUID (a core of red blood cell suspension) and a peripheral layer of plasma MODELled as Newtonian FLUID. The governing equations for the velocity distribution have been solved using a perturbation technique, and the effective dispersion coefficient has been evaluated numerically (FDM) by solving the moment equations. Using the Hermite polynomial representation of central moments the axial distribution of mean concentration is determined. The main objective is to look into the impact of yield stress, peripheral layer thickness, irreversible and reversible reaction rate on the dispersion process. The study has significant applications on the transport of species in a blood flow system.

In the present study TWO-phase flow within the effervescent atomizer has been simulated by the volume of FLUID interface tracing MODEL using 0.08%, 0.32%, 1.24%, and 4.9% gas-to-liquid mass ratios and 0.38 L/min liquid flow rate. The purpose of this simulation is to study TWO-phase flow regimes within the effervescent atomizer and their effect on the atomization quality. This study also considers the gasliquid interface instabilities in different TWO-phase flow regimes inside the atomizer. The compressibility of gas phase, which is not considered in previous researches, is included in this study with the gas-to-liquid mass ratios of 1.24% and 4.9%, due to the high gas phase velocity in constant liquid flow rate and high gas-to-liquid mass ratios. The effect of gravitational force is considered in all simulations. The results of the simulation indicate that by increasing the gas-to-liquid mass ratio, the TWO-phase flow regime inside the discharge passage transfers from bubbly flow regime with long bubbles to annular flow regime. In addition to decreasing the liquid film thickness coming out from discharge orifice (during transform of the flow regime from bubbly flow to annular flow), the liquid interface instabilities increase in the annular flow regime and segregated ligaments from the liquid interface become shorter, thinner and more unstable. This type of regime is the most efficient flow behavior for the effervescent atomizer.