a two server queueing system with single and batch service is considered in this paper. the arrival process is assumed to be poisson and the service rate follows an exponential distribution. server-i serves the customers in both single and batch service, while server-ii serves the customers in batch service only. the laplace transform of the transient and steady state behavior of the model is c...

A steady-state and transient finite element model has been developed to approximate, with simple triangular elements, the two-dimensional advection—diffusion equation for practical river surface flow simulations. Essentially, the space—time Crank—Nicolson—Galerkin formulation scheme was used to solve for a given conservative flow-field. Several kinds of point sources and boundary conditions, na...

Spherical diffusion flames supported on a porous sphere were studied numerically and experimentally. Experiments were performed in 2.2 s and 5.2 s microgravity facilities. Numerical results were obtained from a Chemkin-based program. The program simulates flow from a porous sphere into a quiescent environment, yields both steady-state and transient results, and accounts for optically thick gas-...

In this paper, transient solution of two dimensional asymmetric thermal and mechanical stresses for a hollow cylinder made of piezoelectric material is developed. Transient temperature distribution, as function of radial and circumferential directions and time with general thermal boundary-conditions, is analytically obtained, using the method of separation of variables and<br...

[1] We report results on the effects of porewater pH and transients in porewater flow on the deposition and mobilization of colloid-sized clay particles within unsaturated sand columns. The deposition rates of illite under steady-flow conditions were essentially independent of pH, while the deposition rates of kaolinite nearly doubled as the pH decreased from 7.4 to 4.6. Mobilization of kaolini...

This paper describes and validates transient stability and power flow model of a Unified Power Flow Controller (UPFC), and presents a detailed comparison of different controls strategies, proposing novel, efficient and simple controls for this controller. The proposed model accurately represents the behavior of the controller in quasi-steady state operating conditions, and hence is adequate for...

Water-hammer is a transient condition which may occur in a network as a result of rapid or slow valve closures, pump failures, changes in turbine loading, etc. It creates high and low pressure waves which travel along the system and decay as a result of wall shear stress. Comparison o experimental and theoretical results revealed the failure of steady or quasi-steady models in correctly predict...

This report describes and validates a transient stability and power flow model of a Unified Power Flow Controller (UPFC), and presents a detailed comparison of different controls strategies, proposing novel, efficient and simple controls for this controller. The proposed model accurately represents the behavior of the controller in quasi-steady state operating conditions, and hence is adequate ...