Free Shear Layer Behavior in Rotating Systems

Rothe, P.H.; Johnston, J. P.

doi:10.1115/1.3448721

Cited by 41 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These investigators have documented strong secondary flows and have identified aspects of flow stability which produce streamwise oriented, vortex-like structures in the flow of rotating radial passages. The effects of rotation on the location of flow reattachment after a backward facing step was presented by Rothe and Johnston (1979). This work was especially helpful in understanding the effects of rotation on heat transfer in passages with normal trips.…”

Section: Previous Studiesmentioning

confidence: 99%

Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow

Johnson¹,

Wagner²,

Steuber

et al. 1994

Journal of Turbomachinery

183

View full text Add to dashboard Cite

Experiments were conducted to determine the effects of buoyancy and Coriolis forces on heat transfer in turbine blade internal coolant passages. The experiments were conducted with a large scale, multi-pass, heat transfer model with both radially inward and outward flow. Trip strips. skewed at 45 degrees to the flow direction, were machined on the leading and trailing surfaces of the radial coolant passages. A n analysis of the governing flow equations showed that four parameters influence the heat transfer in rotating passages:coolant-to-wall temperature ratio, rotation number. Reynolds number and radius-to-passage hydraulic diameter ratio. The first three of these four parameters were varied over ranges which are typical of advanced gas turbine engine operating conditions. Results were correlated and compared to previous results from similar stationary and rotating models with smooth walls and with trip strips normal to the flow direction. The heat transfer coefficients on surfaces, where the heat transfer decreased with rotation and huoyancy. decreased to as low as 40 percenl of the value wthout rotation. However, the maximum values of the heat transfer coefficients with high rotation were only slightly above the highest levels previously obtained with the smooth wall model. It was concluded that (1) both Coriolis and buoyancy effects must be considered in turbine blade cooling designs with trip strips. (2) the effects of rotation are markedly different depending upon the flow direction and (3) the heat transfer with skewed trip strips i s less sensitivity to buoyancy than the heat transfer in motleis with either smooth walls or normal trips. Therefore, skewed trip strips rather than normal trip strips are recommended and peometry-specific tests will be required for accurate design information.

show abstract

Section: Previous Studiesmentioning

confidence: 99%

Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow

Johnson¹,

Wagner²,

Steuber

et al. 1994

Journal of Turbomachinery

183

View full text Add to dashboard Cite

show abstract

“…In an earlier study, Rohte and Johnston [1979] experimentally demonstrated that the turbulent shear layer past a backstep for low blockage ratio is more affected under stabilizing rotation (leading side of radially outward flow) than destabilizing rotation (trailing side of radially outward flow). The changes in the first-pass leading and trailing sides are similar to a smooth channel (Han et Beside the Coriolis force in heated rotating ducts, the centrifugal force induces buoyancy effects that can play a major role in the heat transfer patterns.…”

Section: Resultsmentioning

confidence: 99%

Influence of Rotation on Heat Transfer from a Two‐Pass Channel with Periodically Placed Turbulence and Secondary Flow Promoters

Dutta

Han

Zhang

1995

International Journal of Rotating Machinery

View full text Add to dashboard Cite

In a stationary duct, ribs placed at an angle oblique to the main flow direction are more effective in heat transfer enhancement than the ribs placed perpendicular to the flow. Obliquely placed ribs, besides tripping the boundary layer, produce secondary flow patterns to increase heat transfer from the surfaces. Ducts rotating about an axis perpendicular to their own also develop secondary flows. These two secondary flows, produced by oblique ribs and rotation, interact with each other and develop a new heat transfer pattern that is different from those produced by oblique ribs or by rotation alone. This paper uses two types of rib configurations (60 parallel ribs and 60 staggered ribs) as turbulence and secondary flow promoters. The local and surface averaged Nusslt numbers are presented for both stationary and rotating conditions. This experimental study is conducted on a two-pass square channel with two opposite rib roughened surfaces (leading and trailing sides). All the walls are maintained at the same temperature. The heat transfer results in a rotating condition show that the 60 staggered ribs are more effective in the first pass but the 60 parallel ribs do better in the second pass.

show abstract

“…Incompressible flows in rotating fields have been extensively studied by a number of researches [6][7][8][9] to understand air currents in the atmosphere and to grasp turbomachinery flows. Turbulent flows in channel rotating around the spanwise axis were investigated by the LES [10,11] and the DNS [12,13], and the effects of the Coriolis force on the flow stability and turbulent structures were explored.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Rotating Turbulent Channel Flow by the Vortex in Cell Method

Uchiyama¹

2013

TOTPJ

View full text Add to dashboard Cite

Direct numerical simulation (DNS) of a fully-developed turbulent flow in a channel rotating around the spanwise axis is performed. A vortex in cell (VIC) method, of which numerical accuracy was successfully improved by the authors in their prior study, is applied to the DNS. The Reynolds number based on the friction velocity and the channel half width is 171, and the nondimensional rotation number defined with the channel angular velocity and width is 2.1. The simulated turbulence statistics, such as the mean velocity and the Reynolds shear stress, are favorably compared with the existing DNS results. The simulation can analyze the disappearance of the streak structures near the suction-wall due to the channel rotation. It also captures the secondary flow of the Taylor-Görtler vortex pattern near the pressure-wall. These simulation results demonstrate that the VIC method improved by the authors is indeed applicable to the DNS of turbulent flows in rotating channel.

show abstract

Free Shear Layer Behavior in Rotating Systems

Cited by 41 publications

References 0 publications

Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow

Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow

Influence of Rotation on Heat Transfer from a Two‐Pass Channel with Periodically Placed Turbulence and Secondary Flow Promoters

Numerical Simulation of Rotating Turbulent Channel Flow by the Vortex in Cell Method

Contact Info

Product

Resources

About