Development of a Laplacian-based mesh generator for ALE calculations in rotary volumetric pumps and compressors

Voorde, John Vande; Vierendeels, Jan; Dick, Erik

doi:10.1016/j.cma.2003.12.063

Cited by 29 publications

(10 citation statements)

References 7 publications

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“…Vande Voorde et al [1] use a structured mesh in each time step for the simulation of a compressor of two external gears, solving the Laplace equation for a certain potential function in each time step with appropriate boundary conditions. Another technique commonly employed is superposition, as shown in the study of Bruce et al [2].…”

Section: Introductionmentioning

confidence: 99%

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Numerical Analysis of External Gear Pumps Including Cavitation

Campo

Castilla

Raush

et al. 2012

Journal of Fluids Engineering

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Hydraulic machines are faced with increasingly severe performance requirements. The need to design smaller and more powerful machines rotating at higher speeds in order to provide increasing efficiencies has to face a major limitation: cavitation. The problem is inherently three-dimensional, due to the axial clearances, the relief and circumferential grooves, and to the circular pipes through which the fluid enters and exits the pump. A simplified two-dimensional numerical approach by means of computational fluid dynamics (CFD) has been developed for studying the effect of cavitation in the volumetric efficiency of external gear pumps. The assumptions employed prevent from predicting realistic values of the volumetric efficiency, but show to be valid to understand the complex flow patterns that take place inside the pump and to study the influence of cavitation on volumetric efficiency. A method for simulating the contact between solid boundaries by imposing changes in viscosity has been developed. Experiments of unsteady cavitation in water and oil performed by other authors have been numerically reproduced using different cavitation models in order to select the most appropriate one and to adjust its parameters. The influence of the rotational speed of the pump has been analyzed. Cavitation in the suction chamber very effectively damps the water hammer associated to the sudden change of the contact point position at the end of the gearing cycle. At high rotational speeds, the volume of air becomes more stable, reducing the flow irregularity. When cavitation takes place at the meshing region downstream from the contact point, the volume of air that appears acts as a virtual second contact point, increasing the volumetric efficiency of the pump.

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Section: Introductionmentioning

confidence: 99%

“…Outlet flow rate of the reference gear pump at different rotational speeds with and without cavitation1 Animations available in the online version of this paper.…”

mentioning

confidence: 99%

Numerical Analysis of External Gear Pumps Including Cavitation

Campo

Castilla

Raush

et al. 2012

Journal of Fluids Engineering

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“…Voorde et al [7] proposed a grid manipulator based on the ALE method. It is a time-dependent grid generation method that computes grid motions with local flow velocity in a stationary computational grid in a mixed form of Lagrangian and Eulerian methods.…”

Section: Introductionmentioning

confidence: 99%

Performance Characteristics of a 4 × 6 Oil-Free Twin-Screw Compressor

Byeon

Lee²,

Kim

2017

Energies

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The screw compressor in the early stage of development is generally known as the oil-injection type. However, escalating environmental problems and advances in electronic components have spurred continuous R & D to minimize the oil content in compressed air. The oil-free twin-screw compressor is continuously compressed by inner volumetric change between rotors and casing. Fo this reason, in order to predict the overall performance of the screw compressor at the early stage of the design process, industry still relies on the empirical method. However, it is difficult using the existing empirical method to gain more information of the inner fluid flow of the twin-screw compressor. Flow simulation techniques using CFD are required. This study presents applications of a recently proposed overset grid method to the solution of the flow around a moving boundary. In order to analyze the performance of a 4 × 6 oil-free screw compressor, the 3-D, unsteady and compressible flow fields were numerically calculated with a shear stress transport (SST) turbulence model, and implemented by the commercial software, Star-CCM+. The pressure distributions were calculated and graphically depicted. Results also showed that the volumetric and adiabatic efficiencies of the screw compressor measured by the experiments were 78% and 71%, respectively.

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“…Grid cells are defined by the same faces and nodes during the entire simulation, what means that the grid nodes move (ALE, Arbitrary Langrangian-Eulerian method). To generate the twodimensional grids, a grid generation algorithm developed in [13,14] was used. The grid generator only creates the grid in the casing of the machine.…”

Section: Cfd Analysismentioning

confidence: 99%