This paper presents an error test function usable for the local error contro l and the automatic stepsize selection in the numerical integration of general index-1 and index-2 differentialalgebraic equations (DAEs). This test function makes a compromise between a good approximation of the error arising per step by the discretization (local error) and the order and smoothness assumptions made by...

In this paper, the dynamic simulation for a high pressure regulator is performed to obtain the regulator behavior. To analyze the regulator performance, the equation of motion for inner parts, the continuity equation for diverse chambers and the equation for mass flow rate were derived. Because of nonlinearity and coupling, these equations are solved using numerical methods and the results are ...

a numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. the continuity and momentum equations were solved first, assuming the wall reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. the results show that at constant inlet and...

Neural network is one of the new soft computing methods commonly used for prediction of the thermodynamic properties of pure fluids and mixtures. In this study, we have used this soft computing method to predict the coefficients of the Antoine vapor pressure equation. Three transfer functions of tan-sigmoid (tansig), log-sigmoid (logsig), and linear were used to evaluate the performance of diff...

Expressions for a K-adiabatic master equation for a bimolecular recombination rate constant krec are derived for a bimolecular reaction forming a complex with a single well or complexes with multiple well, where K is the component of the total angular momentum along the axis of least moment of inertia of the recombination product. The K-active master equation is also considered. The exact analy...

We consider the steady state equations for a compressible fluid. Since we wish to solve for a range of speeds we must consider the equations in conservation form. For transonic speeds these equations are of mixed type. Hence, the usual approach is to add time derivatives to the steady state equations and then march these equations in time. One then adds a time derivative of the density to the c...

We study dispersive mixed-order systems of pseudodifferential operators in the setting of Lp-Sobolev spaces. Under the weak condition of quasihyperbolicity, these operators generate a semigroup in the space of tempered distributions. However, if the basic space is a tuple of Lp-Sobolev spaces, a strongly continuous semigroup is in many cases only generated if p = 2 or n = 1. The results are app...

A derivation is given of the Boltzmann–Vlasov equation beginning from multiple scattering considerations. The motivation for the discussion, which is purely pedagogical in nature, is the current interest in understanding the origins of transport equations in terms of rigorous field-theory descriptions, or, as in this case, exact nonrelativistic formulations.

A new method has been proposed to introduce an extra parameter to a family of distributions for more flexibility. A special case has been considered in details namely; one parameter exponential distribution. Various properties of the proposed distribution, including explicit expressions for the moments, quantiles, mode, moment generating function, mean residual lifetime, stochastic orders, orde...

  Application of Archie equation in carbonate reservoirs is not easy due to high dependence of its parameters on carbonate characteristics. Carbonates are very heterogeneous in nature and hydrocarbon reserve estimation in these reservoirs of mostly oil-wet and intermediate-wet is highly influenced by the input values of saturation exponent. To our knowledge, non representative oils have been us...