A Combined Experimental/Computational Study of Flow in Turbine Blade Cooling Passage: Part I — Experimental Study

Abstract

A combined experimental/computational study has been performed for flow in a rotating serpentine passage which approximates the internal cooling passage for turbine blades. Experimental results are presented in Part I and computational results, in Part II. Benchmark quality velocity measurements were acquired by laser-Doppler velocimetry at Reynolds number of 25,000 and Rotation number of 0.24. The results were used to assess the influence of the Coriolis force on the velocity characteristics and to explain the heat transfer phenomena observed in Wagner et al (1991). The results showed an increase in streamwise velocity on the high pressure side and a decrease in streamwise velocity on the low pressure due to Coriolis effect. Cross-stream, tangential and rms velocities indicated the presence of swirl, strong secondary flow and large turbulent fluctuations in the vicinity of the turns.

Computation of Compressible Flow and Heat Transfer in a Rotating Duct With Inclined Ribs and a 180-Degree Bend

“…The geometry of that problem is the same as that studied here except for the absence of ribs. For that problem, the computed Nusselt numbers on the leading and trailing walls for the up-leg part of the U-duct were compared with measured one by Wagner, et al (1991a). Those comparisons, described in Stephens,et al (I 996b), showed that very good agreements were obtained.…”

“…Wagner, et al (1991a,b), Morris & Salemi (1992), Han, et al (1994), and Cheah, et al (1996) investigated rotating ducts with smooth walls. Taslim, et al (1991), Wagner, et al (1992), Zhang, et al (1993), Johnson, et al (1994), Zhang, et al (1995), Tse (1995), and Kuo & Hwang (1996) reported studies on rotating ducts with ribbed walls. These investigators studied the effects of Reynolds number (Re), rotation number (Ro), and a buoyancy parameter that accounts for the coolant-to-wall temperature ratio, rotational speed, and the radial position of the coolant duct relative to the axis of rotation.…”

“…Second, develop better physical models and numerical algorithms to improve quantitative predictions. In terms of physical models, Tse, et al (1994) clearly demonstrated the need to account for compressibility (see also Besserman & Tanrikut (1991)) and the need to use a low-Reynolds number turbulence model for the near-wall region (i.e., wall functions may be inadequate). However, what is the best turbulence model or how should turbulence be modified for rotation is still unclear, especially when there are ribs.…”

A 3D-PIV System for Gas Turbine Applications

“…Such measurements have been reported by Tse and Steuber (1997), Tse et al (1994), Iacovides et al (1998), Hsieh et al (1997), Bons and Kerrebrock (1998) and Servouze (1998). However, these flow measurements have all been made with the instrumentation on the stationary frame, and only provide conditionally sampled data.…”

Heat (Mass) Transfer in a Rotating Two‐Pass Square Channel — Part II:Local Transfer Coefficient, Smooth Channel

“…Tse et al (1994), Tse and McGrath (1995), and McGrath and Tse (1995) measured the local velocity distributions in a rotating serpentine channel with smooth walls, and compared their experimental results with distributions that were predicted numerically by solving the relevant governing conservation equations with a Navier-Stokes code by Rhie (1986). Other recent numerical studies on turbulent flow and heat transfer in rotating smooth channels include Prakash and Zerkle (1992) and .…”