scholarly journals Study on Restriction Method for End-Wall Boundary Layer Thickness in Axial Helium Gas Compressor for Gas Turbine High Temperature Gas Cooled Reactor(Fluids Engineering)

2009 ◽  
Vol 75 (749) ◽  
pp. 11-18
Author(s):  
Shoji TAKADA ◽  
Takakazu TAKIZUKA ◽  
Xing YAN ◽  
Kazuhiko KUNITOMI ◽  
Yoshiyuki INAGAKI
Keyword(s):  
Boundary Layer ◽  
High Temperature ◽  
Gas Turbine ◽  
Layer Thickness ◽  
Boundary Layer Thickness ◽  
Wall Boundary Layer ◽  
Helium Gas ◽  
Restriction Method ◽  
End Wall ◽  
High Temperature Gas

Modeling the 3-D Flow Effects on Deviation Angle for Axial Compressor Middle Stages

1986 ◽  
Vol 108 (1) ◽  
pp. 131-137 ◽  
Author(s):  
W. B. Roberts ◽  
G. K. Serovy ◽  
D. M. Sandercock
Keyword(s):  
Boundary Layer ◽  
Layer Thickness ◽  
Boundary Layer Thickness ◽  
Axial Compressor ◽  
Tip Clearance ◽  
Blade Element Theory ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Flow Effects ◽  
End Wall

A model of the spanwise variation of the 3-D flow effects on deviation is proposed for middle-stage rotors and stators. This variation is taken as the difference above or below that predicted by blade element theory at any spanwise location. It was found that the stator variation is strongly affected by the end-wall boundary-layer thickness as well as camber, solidity, and blade channel aspect ratio. Rotor variation was found to depend on end-wall boundary layer thickness and tip clearance normalized by blade span. If these parameters are known or can be calculated, the models provide a reasonable approximation to the spanwise variation of deviation for middle compressor stages operating at low to high subsonic inlet Mach numbers.

Annulus Wall Boundary-Layer Measurements in a Four-Stage Compressor

1986 ◽  
Vol 108 (1) ◽  
pp. 2-6 ◽  
Author(s):  
N. A. Cumpsty
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Layer Thickness ◽  
Boundary Layers ◽  
Boundary Layer Thickness ◽  
Tip Clearance ◽  
The Other ◽  
Wall Boundary Layer ◽  
Multistage Compressors ◽  
Full Design

There are few available measurements of the boundary layers in multistage compressors when the repeating-stage condition is reached. These tests were performed in a small four-stage compressor; the flow was essentially incompressible and the Reynolds number based on blade chord was about 5 • 104. Two series of tests were performed; in one series the full design number of blades were installed, in the other series half the blades were removed to reduce the solidity and double the staggered spacing. Initially it was wished to examine the hypothesis proposed by Smith [1] that staggered spacing is a particularly important scaling parameter for boundary layer thickness; the results of these tests and those of Hunter and Cumpsty [2] tend to suggest that it is tip clearance which is most potent in determining boundary-layer integral thicknesses. The integral thicknesses agree quite well with those published by Smith.

Study on Off-Design Steady State Performances of Helium Gas Turbocompressor for HTGR-GT

2006 ◽  
Author(s):  
Qisen Ren ◽  
Xiaoyong Yang ◽  
Zhiyong Huang ◽  
Jie Wang
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Electric Power ◽  
Gas Turbine ◽  
Thermal Power ◽  
Power Adjustment ◽  
Partial Load ◽  
Helium Gas ◽  
Gas Turbine Cycle ◽  
High Temperature Gas

The high temperature gas-cooled reactor (HTGR) coupled with direct gas turbine cycle is a promising concept in the future of nuclear power development. Both helium gas turbine and compressor are key components in the cycle. Under normal conditions, the mode of power adjustment is to control total helium mass in the primary loop using gas storage vessels. Meanwhile, thermal power of reactor core is regulated. This article analyzes off-design performances of helium gas turbine and compressors for high temperature gas-cooled reactor with gas turbine cycle (HTGR-GT) at steady state level of electric power adjustment. Moreover, performances of the cycle were simply discussed. Results show that the expansion ratio of turbine decreases as electric power reduces but the compression ratios of compressors increase, efficiencies of both turbine and compressors decrease to some extent. Thermal power does not vary consistently with electric power, the difference between these two powers increases as electric power reduces. As a result of much thermal energy dissipated in the temperature modulator set at core inlet, thermal efficiency of the cycle has a widely reduction under partial load conditions.

A Review of Cascade Data on Secondary Losses in Turbines

1970 ◽  
Vol 12 (1) ◽  
pp. 48-59 ◽  
Author(s):  
J. Dunham
Keyword(s):  
Boundary Layer ◽  
Layer Thickness ◽  
Boundary Layers ◽  
Boundary Layer Thickness ◽  
Blade Loading ◽  
Axial Turbine ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Turbine Cascades

Theories and experiments on secondary losses in axial turbine cascades without end clearance are reviewed. A formula is given which correlates the effect of blade loading on secondary losses more successfully than hitherto. However, it is also shown that secondary losses increase with upstream wall boundary layer thickness. Only a tentative expression for that effect can be suggested. In order to predict secondary losses reliably more must be known about these wall boundary layers.

Streakline Flow Visualization of Discrete Hole Film Cooling for Gas Turbine Applications

1976 ◽  
Vol 98 (2) ◽  
pp. 245-250 ◽  
Author(s):  
R. S. Colladay ◽  
L. M. Russell
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Flow Field ◽  
Gas Turbine ◽  
Layer Thickness ◽  
Turbulent Mixing ◽  
Film Cooling ◽  
Boundary Layer Thickness ◽  
Hole Diameter ◽  
Neutrally Buoyant

Film injection from discrete holes in a three row staggered array with 5-dia spacing was studied for three hole angles: (1) normal, (2) slanted 30 deg to the surface in the direction of the mainstream, and (3) slanted 30 deg to the surface and 45 deg laterally to the mainstream. The ratio of the boundary layer thickness-to-hole diameter and the Reynolds number were typical of gas turbine film cooling applications. Results from two different injection locations are presented to show the effect of boundary layer thickness on film penetration and mixing. Detailed streaklines showing the turbulent motion of the injected air were obtained by photographing very small neutrally-buoyant helium filled “soap” bubbles which follow the flow field. Unlike smoke, which diffuses rapidly in the high turbulent mixing region associated with discrete hole blowing, the bubble streaklines passing downstream injection locations are clearly identifiable and can be traced back to their point of ejection.

Influence of the wall boundary layer thickness on a gas jet injected into a liquid crossflow

2001 ◽  
Vol 30 (4) ◽  
pp. 458-466 ◽  
Author(s):  
O. Vigneau ◽  
S. Pignoux ◽  
J. L. Carreau ◽  
F. Roger
Keyword(s):  
Boundary Layer ◽  
Layer Thickness ◽  
Boundary Layer Thickness ◽  
Gas Jet ◽  
Wall Boundary Layer ◽  
Wall Boundary

Characteristics of the Flow Past a Wall-Mounted Finite-Length Square Cylinder at Low Reynolds Number With Varying Boundary Layer Thickness

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Sachidananda Behera ◽  
Arun K. Saha
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Flow Field ◽  
Layer Thickness ◽  
Finite Length ◽  
Boundary Layer Thickness ◽  
Square Cylinder ◽  
Near Wake ◽  
Wall Boundary Layer ◽  
Wall Boundary

Direct numerical simulation (DNS) is performed to investigate the modes of shedding of the wake of a wall-mounted finite-length square cylinder with an aspect ratio (AR) of 7 for six different boundary layer thicknesses (0.0–0.30) at a Reynolds number of 250. For all the cases of wall boundary layer considered in this study, two modes of shedding, namely, anti-symmetric and symmetric modes of shedding, were found to coexist in the cylinder wake with symmetric one occurring intermittently for smaller time duration. The phase-averaged flow field revealed that the symmetric modes of shedding occur only during instances when the near wake experiences the maximum strength of upwash/downwash flow. The boundary layer thickness seems to have a significant effect on the area of dominance of both downwash and upwash flow in instantaneous and time-averaged flow field. It is observed that the near-wake topology and the total drag force acting on the cylinder are significantly affected by the bottom-wall boundary layer thickness. The overall drag coefficient is found to decrease with thickening of the wall boundary layer thickness.

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