High Reynolds number flow in a moving corner

Tabaczynski, R. J.; Hoult, David P.; Keck, James C.

doi:10.1017/s0022112070001234

Cited by 87 publications

(45 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The vertical walls move simultaneously with an oscillatory velocity while the horizontal walls are the fixed pistons, similar to the experimental arrangement used by Tabaczynski et al [4]. For water as the working fluid, the vertical and horizontal dimensions of the cavity are H = 7.5 × 10 −2 m and D = 5.0 × 10 −2 m, respectively.…”

Section: Physical and Geometry Descriptionmentioning

confidence: 99%

“…In the above approximation the degrees of freedom for the velocity of the fluid are located on the vertices of each triangle τ h/2 , while the degrees of freedom for the pressure are located on the vertices of each triangle in τ h , as shown in figure (2). Using the above finite dimensional spaces leads to the following approximation of equations (3)(4)(5)(6).…”

Section: Finite Element Approximationmentioning

confidence: 99%

“…According to Tabaczynski et al [4], the flow near the corner is equivalent in both cases provided √ νt/U w T ≪ 1 , where ν is the kinematic viscosity, t is the time, U w is the instantaneous piston speed, and T is the period. The pioneering experimental observations of Tabaczynski et al [4] have shown that the fluid motion is a sink-type flow when the cylinder wall retreats from the piston and a spiral ring vortex motion near the piston face and cylinder wall interface when the cylinder wall moves toward the piston, both for constant and oscillatory velocity of the walls. The flow in the vicinity of the corner as the wall moves towards a fixed piston with a steady motion was studied theoretically by Taylor [5] and Batchelor [6], assuming that the inertial effects can be neglected.…”

Section: Introductionmentioning

confidence: 99%

“…Tabaczynski et al [4] and Allen and Chong [7] studied the dimension of the vortex generated when the lateral wall moves towards the piston. The first authors considered constant and sinusoidal wall speed while Allen and Chong [7] observed the phenomenon for constant or power law wall speed.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Vortex formation in a cavity with oscillating walls

et al. 2009

View full text Add to dashboard Cite

The vortex formation in a two-dimensional Cartesian cavity, which their vertical walls move simultaneously with an oscillatory velocity and the horizontal walls are fixed pistons, is studied numerically.The governing equations were solved with a finite element method combined with an operator splitting scheme. We analyzed the behavior of vortical structures occurring inside a cavity with an aspect ratio of height to width of 1.5 for three different displacement amplitudes of the vertical oscillatory walls (amplitude/width= Y = 0.2, 0.4 and 0.8) and Reynolds numbers based on the cavity width of 50, 500 and 1000. Two vortex formation mechanisms are identified: a) the shear, oscillatory motion of the moving boundaries coupled with the fixed walls that provide a translational symmetry-breaking effect and b) the sharp changes in the flow motion when the flow meets the corners of the cavity. The vortices cores were identified using the Jeong-Hussain criterium and it is found that they occupy smaller areas as the Reynolds number increases. All flows studied are cyclic symmetric and for low Y and Re values they are also symmetric with respect to the vertical axis dividing the cavity in two sides. In asymmetric flows, the unbalance between the vortices on each side of the mid-vertical line generates a vortex that occupies the central part of the cavity. The breakdown of the axial symmetry was studied for a fixed value of the oscillation amplitude, Y = 0.8, taking Re as the bifurcation parameter. The results indicates that the symmetry is broken through a supercritical pitchfork bifurcation.

show abstract

Section: Physical and Geometry Descriptionmentioning

confidence: 99%

Section: Finite Element Approximationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Vortex formation in a cavity with oscillating walls

et al. 2009

View full text Add to dashboard Cite

show abstract

“…the region unaffected by direct boundary-layer heat transfer). 3 The cool gas mixes with compressed core gas in a complex flow field, leading to an inhomogeneous temperature field which cannot be easily predicted. 4 The impact of the corner vortex can be reduced or even eliminated by introducing an annular gap between the piston and cylinder, with a crevice of sufficient volume to contain much of the boundary-layer gas.…”

Section: Introductionmentioning

confidence: 99%

Simplified Approach to the Prediction and Analysis of Temperature Inhomogeneity in Rapid Compression Machines

et al. 2015

View full text Add to dashboard Cite

1Substantial progress has been made in understanding and reducing temperature inhomogeneity in rapid compression machines (RCMs) with the help of computational modelling. To date, however, it has not been possible to investigate and map the full range of possible RCM designs, working gases and operating conditions. In this article, we present a framework which simplifies the task of comprehensive and general RCM performance prediction. A set of thermophysical and geometrical parameters have been defined to characterize the design and operating conditions of a general RCM. Dimensional analysis was applied to reduce the number of variables and a sensitivity analysis, based on computational simulations, was used to rank the dimensionless parameters and eliminate unimportant ones. The results of this analysis show that Reynolds number, Prandtl number, aspect ratio, and crevice volume ratio are the most important parameters determining temperature inhomogeneity.A further set of computational simulations was conducted to predict post-compression temperature inhomogeneity over the full range of RCM design and operating parameters. These results are well represented by a simple power law equation that correlates a dimensionless temperature inhomogeneity parameter (mass-averaged over the main chamber) as a function of post-compression time with just three parameters -Peclet number (the product of Reynolds and Prandtl numbers), aspect ratio, and crevice volume ratio. This equation can serve as a simple and general tool for RCM designers and users who wish to determine optimal configurations that minimise temperature inhomogeneity for combustion experiments.2

show abstract

A simple method to study gas phase reactions

Morrison

Reimer

1987

AIChE Journal

View full text Add to dashboard Cite

To understand better the impact of gas phase reactions on chemical vapor deposition, a new experimental method has been developed to isolate and study homogeneous reactions separately from heterogeneous reactions. This new system heats reactant gases by rapidly compressing them to temperatures greater than 1,000 K; the walls of the reactor remain constant at 500 K or less. Pressure and volume measurements determine the mean temperature of the gas. Results from a series of test reactions and simple models show that this apparatus and measurement method work well. The apparatus is inexpensive and simple to use, and has advantages over shock tubes and static systems.

show abstract

High Reynolds number flow in a moving corner

Cited by 87 publications

References 1 publication

Vortex formation in a cavity with oscillating walls

Vortex formation in a cavity with oscillating walls

Simplified Approach to the Prediction and Analysis of Temperature Inhomogeneity in Rapid Compression Machines

A simple method to study gas phase reactions

Contact Info

Product

Resources

About