Comparison of Two-Equation Turbulence Models for Prediction of Heat Transfer on Film-Cooled Turbine Blades

Abstract

A Ihree-dimensional Ntw~r-StoUs code IrJJS beell used to cotrI/IUU 1M heJlJ~., coef/iciml 011 two fiIm-eookd turbine b1DJks, 1IQ1IIe/y, 1M JIKI rotor with six rows of cooling holes, induJling three rows 011 1M shower Mad, and 1M C3X VIlM with niM rows of holes, induding five rows 011 1M shower heIJd. Pmlidions ofheJlJ tmnsfer coef/icielllat the bItule SUlfa« using three hf>o-equatioll turbuJmce motfels, specijieoJly, Cookley's q·w model, Chiell's t-e motfet, and WIIcar's k-o» model with Melller's modijieations, luwe been compand with 1M experimmtot t1IJJIl of Camei and Arts £11for 1M VKl rotor, and ofHyltoll el aI. 121for the C3X VIlM along with pretlidions using the Ba/dwin-Lo1ll/U (B-O model tIIkm from Gtug and Gaugler 131. II is foruul t1UIl for 1M CDS" considered here the twoequatioll motlds pretlid the btDde heJlJ~er somewhat better Ihtm 1M B-L model ex«pI immediote/y downstrttJm of the jiIm-cooling holes 011 1M suction SUIf-of 1M JIKI rotor, and over nwsI of 1M suaion surf-of 1M C3X VIlM. However, all hf>o-equatiOIl motfels require 40% more computer core than the B·L motfelfor solution, and while 1M q.w and t-e motfels need 40% mDre computer nine Ihtm 1M B-L motfet, the t-w model reqIIin3 at least 65% more nine becou.se of 1M slower tYlU of convergmt:e. II is loruul t1UIl 1M heJlJ tmnsfer coejJicielll uhibils a strollgspallwiseas wellas stretlmwise variationlor both b1DJks and all turbulence motfels.

Convective Heat Transfer on An Inlet Guide Vane

“…On the pressure side the calculated and the experimental results agree well, although the transition back to turbulence occurs earlier for the calculated results than for the experimental results. For the suction side the calculated values are much higher than the experimental ones, which has been found in the literature by others as well, see, e.g., Garg and Rigby5, Garg and Ameri6, and Dahlander7. The sudden jumps due to imperfections in the blade surface description can also be found here for 0.455 < s/smax < 0.65.…”

Heat transfer on a film-cooled rotating blade using different turbulence models

“…A single-block version of the same code, modified for filmcooling applications, was used by Garg and co-workers for the film cooling studies described earlier. The k-ω model of Wilcox (1994) with Menter's modifications (Menter, 1993) has yielded good results for heat transfer on film-cooled blades (Garg and Ameri, 1997;Garg, 1999), and is highly desirable for multi-block codes since it does not require the computation of distance from a wall. Also, no wall functions are used, thus avoiding any bias to the complex interactions between the coolant and the mainstream near the blade surface.…”

“…Several further studies in this field have been summarized by Garg and Gaugler (1993, 1994, 1996. A number of parametric studies have been performed by Garg and co-workers to determine the effect of several parameters, such as the effect of coolant velocity and temperature distributions at the hole exit (Garg and Gaugler, 1997b), the effect of blade rotation and of the direction of coolant injection from the shower-head holes (Garg, 1997), the effect of spanwise pitch of shower-head holes (Garg and Gaugler, 1996), the effect of coolant to mainstream mass flow and temperature ratio (Garg and Gaugler, 1997a), and the effect of turbulence modeling (Garg and Abhari, 1997;Garg and Ameri, 1997;Garg, 1998Garg, , 1999. Four turbulence models, the Baldwin-Lomax model, Coakley's q-ω model, Chien's k-ε model, and Wilcox's k-ω models have been analyzed, and results compared with the experimental data for heat transfer from rotating as well as stationary blades.…”

Convective heat transfer in cross-corrugated triangular ducts under uniform heat flux boundary conditions

“…As an alternative, in this investigation, a low Reynolds k-x model is employed. Unlike the k-e model, it is easier to prescribe the boundary conditions in the k-x model [15,16]. We know that k = 0 on solid boundaries, and x can be specified at the first few grid points away from the wall as x ¼ 6l by 2 , (y the distance to wall).…”