The present work deepens the analysis of the flow field inside a triangular equilateral channel with turbulence promoters, perpendicular to the radial direction, on both leading and trailing sides, under rotation and both isothermal and nonisothermal conditions (i.e. with centrifugal buoyancy forces). Simulations have been performed at constant Re = 10,000, Ro = 0–0.2–0.6, and Bo = 0–0.08–0.7, the latter corresponding to 80℃ temperature difference between fluid and walls. These conditions match those of the particle image velocimetry measurements, used for comparison against predictions. After proper validation, the numerical modeling helped with the assessment of the flow field evolution along the radial extension of the cooling channel. It has been possible to determine the path of the coolant throughout the channel and localize where the heat transfer would have been enhanced/decreased by secondary flow structures, with respect to the stationary case. Furthermore, a rather Bo-independency of the flow field in this kind of geometry has been confirmed. The analysis presented in this paper finds support from the thermal data available from the open literature, which is rich of thermal analysis indeed, but lacks a detailed description of internal flow fields.
JohnstonJPHalleenRPLeziusDK. Effects of spanwise rotation on the structure of two-dimensional fully developed turbulent channel flow. J Fluid Mech1972; 56: 533–557.
2.
SpezialeCGThangamS. Numerical study of secondary flows and roll-cell instabilities in rotating channel flow. J Fluid Mech1983; 130: 377–395.
3.
PascottoMArmelliniAMucignatC. Coriolis effects on the flow field inside a rotating triangular channel for leading edge cooling. ASME J Turbomach2011; 136: 031019–031019.
4.
ColettiFLo JaconoDCresciI. Turbulent flow in rib-roughened channel under the effect of Coriolis and rotational buoyancy forces. Phys Fluids2014; 26: 045111–045111.
5.
FurlaniLArmelliniACasarsaL. Effects of rotation and buoyancy forces on the flow field behavior inside a triangular rib roughened channel. J Turbomach2017; 139: 051001–051001-11.
6.
MetzgerDEVedulaRP. Heat transfer in triangular channels with angled roughness ribs on two walls. Exp Heat Transfer1987; 1: 31–44.
7.
AhnSWSonKP. Heat transfer and pressure drop in the roughened equilateral triangular duct. Int Commun Heat Mass Transfer2002; 29: 479–488.
8.
AmroMWeigandBPoserR. An experimental investigation of the heat transfer in a ribbed triangular cooling channel. Int J Therm Sci2007; 46: 491–500.
9.
Lee DH, Rhee DH and Cho HH. Heat transfer measurements in a rotating equilateral triangular channel with various rib arrangements. In: ASME turbo expo 2006, Barcelona, Spain, 8–11 May 2006, paper no. GT2006-90973.
10.
LiuYHHuhMRheeDH. Heat transfer in leading edge, triangular shaped cooling channels with angled ribs under high rotation numbers. ASME J Turbomach2009; 131: 041017–041017.
11.
LiuYHHuhMHanJC. High rotation number effect on heat transfer in a triangular channel with 45 deg, inverted 45 deg, and 90 deg ribs. ASME J Heat Transfer2010; 132: 071702–071702.
12.
DuttaSHanJCLeePC. Local heat transfer in a rotating two-pass ribbed triangular duct with two model orientations. Int J Heat Mass Transfer1996; 39: 707–715.
13.
Luo DD, Leung CW and Chan TL. Numerical study of turbulent flow in a triangular duct with internal ribbed surfaces. In: Springer proceedings in physics, vol. 109, Progress in turbulence II, 2005, pp.275–278.
14.
Bredberg J. Turbulence modelling for internal cooling of gas-turbine blades. PhD Thesis, Chalmers University of Technology, Sweden, 2002.
15.
TaslimMEFongMKH. Experimental and numerical crossover jet impingement in a rib-roughened airfoil trailing-edge cooling channel. J Turbomach2013; 135: 051014–051014.
16.
Pascotto M, Armellini A, Casarsa L, et al. Numerical aero-thermal analysis of a rib-roughened trailing edge cooling channel at different rotation numbers and channel orientations. In: ASME turbo expo 2014, Düsseldorf, Germany, 16–20 June 2014, paper no. GT2014-25479.
17.
PengWJiangPXWangYP. Experimental and numerical investigation of convection heat transfer in channels with different types of ribs. Appl Therm Eng2011; 31: 2702–2708.
18.
ZhengNLiuPShanF. Effects of rib arrangements on the flow pattern and heat transfer in an internally ribbed heat exchanger tube. Int J Therm Sci2016; 101: 93–105.
19.
SchülerMDreherHMNeumannSO. 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. ASME J Turbomach2012; 134: 021021–021021.
20.
Borello D, Rispoli F and Properzi E. LES-based assessment of rotation-sensitized urbulence models for prediction of heat transfer in internal cooling channels of turbine blades. ASME turbo expo 2016, Seoul, South Korea, 13–17 June 2016, paper no. GT2016-57293.
21.
Sewall EA and Tafti DK. Large eddy simulation of the developing region of a rotating ribbed internal turbine blade cooling channel. In: ASME turbo expo 2004, Vienna, Austria, 14–17 June 2004, paper no. GT2004-53833.
22.
Kubacki S, Rokicki J and Dick E. Hybrid RANS/LES of flow in a rib-roughened rotating channel. In: ASME turbo expo 2014, Düsseldorf, Germany, 16–20 June 2014, paper no. GT2014-26194.
23.
SewallEATaftiDT. Large eddy simulation of flow and heat transfer in the developing flow region of a rotating gas turbine blade internal cooling duct with Coriolis and buoyancy forces. ASME J Turbomach2007; 130: 011005–011005.
24.
BurberiEMassiniDCocchiL. Effect of rotation on a gas turbine blade internal cooling system: Numerical investigation. ASME J Turbomach2016; 139: 031005–031005.
25.
MucignatCArmelliniACasarsaL. Flow field analysis inside a gas turbine trailing edge cooling channel under static and rotating conditions: Effect of ribs. Int J Heat Fluid Flow2013; 42: 236–250.
26.
ArmelliniAMucignatCCasarsaL. Flow field investigations in rotating facilities by means of stationary PIV systems. Meas Sci Technol2012; 23: 025302–025302.
27.
ElebiaryKTaslimME. Experimental/numerical crossover jet impingement in an airfoil leading-edge cooling channel. ASME J Turbomach2012; 135: 011037–011037.
28.
PatilSTaftiD. Large-eddy simulation with zonal near wall treatment of flow and heat transfer in a ribbed duct for the internal cooling of turbine blades. ASME J Turbomach2013; 135: 031006–031006.
