In this paper, an approximate solution of sensitivity matrix of required velocity with final velocity constraint is derived using a piecewise linear gravity assumption. The total flight time is also fixed for the problem. Simulation results show the accuracy of the method. Increasing the midway points for linearization, increases the accuracy of the solution, which this, in turn, depends on the...

This master thesis focused on optimizing the outlet geometry of microcolumn chips and how the chips are assembled in a miniaturized gas analysis system based on the principles of gas chromatography. The theory and literature of gas chromatography at microscales was studied and consequently several outlet designs were simulated with COMSOL Multiphysics®. Their theoretical velocity profiles were ...

An external liquid circulation is introduced into a traditional internal loop reactor in order to improve liquid circulation and increase the interface between gas and liquid phases. The effects of superficial gas velocity and external liquid circulation velocity on local and overall gas holdups are explored experimentally and numerically in the loop section of a combined gas-liquid contactor, ...

Introduction The formatIOn of periodIC patterns (stnatlOn) has drawn much attentIon In contInUOUS wave laser cutt time (s) tp time penod per oxidation cycle (s) U gas velOCIty profile (m/s) Uo streamwlse gas velOCIty (m/s) V Interfacial velOCIty (m/s) u lIqUId velOCIty In x dIrectIOn (m/s) v hqUId velOCIty In y dIrectIOn or cuttIng speed (m1s) v. fnctIon velOCIty (m/s) W actIvatIOn energy (J) W...

The structure of an infinitely strong shock wave (i.e., a shock wave with infinitely large upstream Mach number) is investigated on the basis of the Boltzmann equation. The velocity distribution function is expressed as a sum of a multiple of the Dirac delta function, centered at the upstream bulk velocity, and a remainder. Strong evidence that the remainder has a singularity in the molecular v...

We present evidence that the high-velocity C ivλ1549 emission line gas of radio-loud quasars may originate in a disk-like configuration, in close proximity to the accretion disk often assumed to emit the low-ionization lines. For a sample of 36 radio-loud z ≈2 quasars we find the 20–30% peak width to show significant inverse correlations with the fractional radio core-flux density, R, the radio...

In this paper computational analysis of pressure and velocity in coal combustion system using the fluent software is analysed. The combustion of coal is used in circulating fluidized bed combustion system. This work is concerned about gas–solid two-phase mixtures flowing upwards through the fast beds. The type of information resulting from various ways of analyzing the pressure variations and t...

We consider an ideal gas of massive hadrons in thermal and chemical equilibrium. The gas expands longitudinally in an adiabatic way. This evolution for a baryonless gas reduces to a hydrodynamic expansion. Cooling process is parametrized by the sound velocity. The sound velocity is temperature dependent and is strongly influenced by hadron mass spectrum. ∗Work partially supported by the Polish ...

Gas-phase velocity fluctuations in fixed particle beds and freely evolving suspensions are quantified using particle-resolved direct numerical simulation (PR-DNS). The flow regime corresponds to homogeneous gas-solid systems typically encountered in fluidized bed risers, with high solid to gas density ratio and particle diameter being greater than the dissipative length scales. The contribution...