CFD based study of fluid flow and heat transfer effect for novel turning tool configured with internal cooling channel

2022 ◽  
Vol 73 ◽  
pp. 164-176
Author(s):  
Rohit Singh ◽  
Varun Sharma
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Transfer Effect ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Flow And Heat Transfer

Numerical Predictions of the Effect of Rotation on Fluid Flow and Heat Transfer in an Engine-Similar Two-Pass Internal Cooling Channel With Smooth and Ribbed Walls

2010 ◽  
Author(s):  
M. Schu¨ler ◽  
H.-M. Dreher ◽  
S. O. Neumann ◽  
B. Weigand ◽  
M. Elfert
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Flow Field ◽  
Secondary Flow ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Flow And Heat Transfer ◽  
Numerical Predictions ◽  
Smooth Channel ◽  
Secondary Flow Field

In the present study, a two-pass internal cooling channel with engine-similar cross-sections was investigated numerically. The channel featured a trapezoidal inlet pass, a sharp 180° bend and a nearly rectangular outlet pass. Calculations were conducted for a configuration with smooth walls and walls equipped with 45° skewed ribs (P/e = 10, e/dh = 0.1) at a Reynolds number of Re = 50,000. The present study focused on the effect of rotation on fluid flow and heat transfer. The investigated rotation numbers were Ro = 0.0 and 0.10. The computations were performed by solving the Reynolds-averaged Navier-Stokes equations (RANS method) with the commercial Finite-Volume solver FLUENT using a low-Re k-ω-SST turbulence model. The numerical grids were block-structured hexahedral meshes generated with POINTWISE. Flow field measurements were independently performed at DLR using Particle Image Velocimetry. In the smooth channel rotation had a large impact on secondary flows. Especially, rotation induced vortices completely changed the flow field. Rotation also changed flow impingement on tip and outlet pass side wall. Heat transfer in the outlet pass was strongly altered by rotation. In contrast to the smooth channel, rotation showed less influence on heat transfer in the ribbed channel. This is due to a strong secondary flow field induced by the ribs. However, in the outlet pass Coriolis force markedly affected the rib induced secondary flow field. The influence of rotation on heat transfer was visible in particular in the bend region and in the second pass directly downstream of the bend.

Numerical Predictions of the Effect of Rotation on Fluid Flow and Heat Transfer in an Engine-Similar Two-Pass Internal Cooling Channel With Smooth and Ribbed Walls

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
M. Schüler ◽  
H.-M. Dreher ◽  
S. O. Neumann ◽  
B. Weigand ◽  
M. Elfert
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Flow Field ◽  
Secondary Flow ◽  
Navier Stokes ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Flow And Heat Transfer ◽  
Smooth Channel ◽  
Secondary Flow Field

In the present study, a two-pass internal cooling channel with engine-similar cross-sections was investigated numerically. The channel featured a trapezoidal inlet pass, a sharp 180 deg bend, and a nearly rectangular outlet pass. Calculations were done for a configuration with smooth walls and walls equipped with 45 deg skewed ribs (P/e=10, e/dh=0.1) at a Reynolds number of Re=50,000. The present study focused on the effect of rotation on fluid flow and heat transfer. The investigated rotation numbers were Ro=0.0 and 0.10. The computations were performed by solving the Reynolds-averaged Navier–Stokes equations (Reynolds-averaged Navier–Stokes method) with the commercial finite-volume solver FLUENT using a low-Re shear stress transport (SST) k-ω turbulence model. The numerical grids were block-structured hexahedral meshes generated with POINTWISE. Flow field measurements were independently performed at German Aerospace Centre Cologne using particle image velocimetry. In the smooth channel, rotation had a large impact on secondary flows. Especially, rotation induced vortices completely changed the flow field. Rotation also changed flow impingement on the tip and the outlet pass sidewall. Heat transfer in the outlet pass was strongly altered by rotation. In contrast to the smooth channel, rotation showed less influence on heat transfer in the ribbed channel. This is due to a strong secondary flow field induced by the ribs. However, in the outlet pass, Coriolis forces markedly affected the rib induced secondary flow field. The influence of rotation on heat transfer was visible in particular in the bend region and in the second pass directly downstream of the bend.

scholarly journals Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel

2005 ◽  
Vol 2005 (1) ◽  
pp. 36-44 ◽  
Author(s):  
R. Ben-Mansour ◽  
L. Al-Hadhrami
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Mass Flow Rate ◽  
Heat Transfer Rate ◽  
Turbine Blade ◽  
Flow Rate ◽  
Transfer Rate ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Flow And Heat Transfer

Internal cooling is one of the effective techniques to cool turbine blades from inside. This internal cooling is achieved by pumping a relatively cold fluid through the internal-cooling channels. These channels are fed through short channels placed at the root of the turbine blade, usually called entrance region channels. The entrance region at the root of the turbine blade usually has a different geometry than the internal-cooling channel of the blade. This study investigates numerically the fluid flow and heat transfer in one-pass smooth isothermally heated channel using the RNGk−εmodel. The effect of Reynolds number on the flow and heat transfer characteristics has been studied for two mass flow rate ratios (1/1and1/2) for the same cooling channel. The Reynolds number was varied between10 000and50 000. The study has shown that the cooling channel goes through hydrodynamic and thermal development which necessitates a detailed flow and heat transfer study to evaluate the pressure drop and heat transfer rates. For the case of unbalanced mass flow rate ratio, a maximum difference of8.9% in the heat transfer rate between the top and bottom surfaces occurs atRe=10 000while the total heat transfer rate from both surfaces is the same for the balanced mass flow rate case. The effect of temperature-dependent property variation showed a small change in the heat transfer rates when all properties were allowed to vary with temperature. However, individual effects can be significant such as the effect of density variation, which resulted in as much as9.6% reduction in the heat transfer rate.

3-D Internal Flow and Conjugate Calculations of a Convective Cooled Turbine Blade With Serpentine-Shaped and Ribbed Channels

1999 ◽  
Author(s):  
Dieter E. Bohn ◽  
Volker J. Becker ◽  
Karsten A. Kusterer ◽  
Yokiu Otsuki ◽  
Takao Sugimoto ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Turbine Blade ◽  
Solid Body ◽  
Gas Turbines ◽  
Heat Transfer Analysis ◽  
Numerical Code ◽  
Cooling Channel ◽  
Flow And Heat Transfer ◽  
Body Regions

Modern cooling configurations for turbine blades include complex serpentine-shaped cooling channel geometries for internal-forced convective cooling. The channels are ribbed in order to enhance the convective beat transfer. The design of such cooling configurations is within the power of modem CFD-codes with combined heat transfer analysis in solid body regions. One approach is the conjugate fluid flow and heat transfer solver, CHT-Flow, developed at the Institute of Steam and Gas Turbines, Aachen University of Technology. It takes into account of the mutual influences of internal and external fluid flow and heat transfer. The strategy of the procedure is based on a multi-block-technique and a direct coupling module for fluid flow regions and solid body regions. The configuration under investigation in the present paper is based on a test design of a convective cooled turbine blade with serpentine-shaped cooling passages and cooling gas ejection at the blade tip and the trailing edge. The numerical investigations focus on secondary flow phenomena in the ducts and on the heat transfer analysis at the cooling channel walls. In the first part, the cooling channels are investigated with adiabatic smooth & ribbed walls. The calculations are carried out for the stationary and rotating configuration. Concerning the heat transfer analysis, the results of the ribbed configuration with a fixed thermal boundary condition at the walls in the stationary case are presented. Furthermore, in order to demonstrate the capability of the conjugate method to work without thermal boundary conditions, the cooling configuration is calculated including the external blade flow and the blade walls with internal and external heat transfer under typical operation conditions of gas turbines. The numerical code is used to determine the blade surface temperatures.

Numerical investigation of fluid flow structure and heat transfer in a passage with continuous and truncated V-shaped ribs

2015 ◽  
Vol 25 (1) ◽  
pp. 171-189 ◽  
Author(s):  
Shian Li ◽  
Gongnan Xie ◽  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Thermal Performance ◽  
Internal Cooling ◽  
Transfer Enhancement ◽  
Content Type ◽  
Flow And Heat Transfer

Purpose – The employment of continuous ribs in a passage involves a noticeable pressure drop penalty, while other studies have shown that truncated ribs may provide a potential to reduce the pressure drop while keeping a significant heat transfer enhancement. The purpose of this paper is to perform computer-aided simulations of turbulent flow and heat transfer of a rectangular cooling passage with continuous or truncated 45-deg V-shaped ribs on opposite walls. Design/methodology/approach – Computational fluid dynamics technique is used to study the fluid flow and heat transfer characteristics in a three-dimensional rectangular passage with continuous and truncated V-shaped ribs. Findings – The inlet Reynolds number, based on the hydraulic diameter, is ranged from 12,000 to 60,000 and a low-Re k-e model is selected for the turbulent computations. The local flow structure and heat transfer in the internal cooling passages are presented and the thermal performances of the ribbed passages are compared. It is found that the passage with truncated V-shaped ribs on opposite walls provides nearly equivalent heat transfer enhancement with a lower (about 17 percent at high Reynolds number of 60,000) pressure loss compared to a passage with continuous V-shaped ribs or continuous transversal ribs. Research limitations/implications – The fluid is incompressible with constant thermophysical properties and the flow is steady. The passage is stationary. Practical implications – New and additional data will be helpful in the design of ribbed passages to achieve a good thermal performance. Originality/value – The results imply that truncated V-shaped ribs are very effective in improving the thermal performance and thus are suggested to be applied in gas turbine blade internal cooling, especially at high velocity or Reynolds number.

Study on Flow and Heat Transfer Characteristics of a New-Proposed Alternating Elliptical U-Channel

2020 ◽  
Author(s):  
Kun Xiao ◽  
Juan He ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Cross Section ◽  
Internal Cooling ◽  
Short Axis ◽  
Cooling Channel ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
First Pass ◽  
The Cross

Abstract This paper proposed an alternating elliptical U-shaped internal cooling channel and investigated the flow and heat transfer characteristics, based on the optimal flow field structure deduced from the Field Synergy Principle. The channel consisted of the straight sections and the transition sections. In the straight sections, the cross section of the channel is ellipse, and in the transition sections, the long axis gradually shortened into the short axis, and the short axis gradually expanded to the long axis. However, the cross-section area of the channel remained unchanged. Numerical simulations were performed to solve 3D steady Reynolds-averaged Navier-Stokes equations (RANS) with the standard k-ε turbulence model. The influence of alternating of the cross section on heat transfer and pressure drop of the channel was studied by comparing with the smooth elliptical U-shaped channel, and all the cases were conducted with the Re numbers from 10,000 to 40,000. On this basis, the investigation on alternating elliptical U-shaped internal cooling channel performance was made mainly into two parts. One was the effect of aspect ratio which was set as from 1.1 to 2.0, while the other was the effect of alternating angle θ which was set as from 10° to 90°. The results showed that for the flow field, there was no vortex in the first pass of the smooth elliptical U-shaped channel. On the contrary, in the first pass of the alternating elliptical U-shaped channel, after the transition section, for different Re numbers, four or eight longitudinal vortices were generated. In the second pass, the flow separation in smooth elliptical U-shaped channel was serious because of the centrifugal force at the elbow, while the alternating elliptical channel restrained the flow separation to a certain extent and formed a double-vortex structure just like the vortex cooling. The average Nusselt number of the alternating elliptical U-shaped channel was significantly higher than that of the straight channel, but the pressure loss increased slightly. In addition, with the increase of aspect ratio, the thermal performance of the channel increased in the study range, and when the alternating angle is between 40° to 90°, the thermal performance nearly kept constant and the best.

Sign in / Sign up

Export Citation Format

Share Document