A technique for measuring convective heat transfer at rough surfaces

A new method of measuring local heat transfer coefficients to rough surfaces has been developed. The technique was applied to an idealised section of a large-scaled model of a turbine blade cooling passage to assess the effect of surface irregularities which result from the blade manufacturing process. The experimental method is described in full, and the results are presented for tests on an isolated pin-fin situated in fully developed channel flow. The heat transfer coefficients measured to the rough surface of a plain passage were found to be in excellent agreement with that predicted from velocity measurements.

[1]  T. V. Jones,et al.  Detailed measurements of heat transfer on and around a pedestal in fully developed passage flow , 1986 .

[2]  T. V. Jones,et al.  A comparison of the transient and heated-coating methods for the measurement of local heat transfer coefficients on a pin fin , 1988 .

[3]  L. M. Russell,et al.  Evaluation of a Method for Heat Transfer Measurements and Thermal Visualization Using a Composite of a Heater Element and Liquid Crystals , 1981 .

[4]  M. J. Lewis.  An Elementary Analysis for Predicting the Momentum- and Heat- Transfer Characteristics of a Hydraulically Rough Surface , 1975 .

[5]  Terry V. Jones,et al.  Detailed Heat Transfer Measurements Near and Within the Entrance of a Film Cooling Hole , 1988 .

[6]  H. Schlichting,et al.  Experimentelle Untersuchungen zum Rauhigkeitsproblem , 1936 .

[7]  Terry V. Jones,et al.  High-resolution heat-transfer-coefficient maps applicable to compound-curve surfaces using liquid crystals in a transient wind tunnel , 1987 .

[8]  T. V. Jones,et al.  Techniques for Obtaining Detailed Heat Transfer Coefficient Measurements Within Gas Turbine Blade and Vane Cooling Passages , 1983 .

[9]  M. J. Holland,et al.  Rotor blade cooling in high pressure turbines , 1980 .

[10]  E. Achenbach,et al.  The effect of surface roughness on the heat transfer from a circular cylinder to the cross flow of air , 1977 .

[11]  R. W. Ainsworth,et al.  Measurements of Heat Transfer in Circular, Rectangular and Triangular Ducts, Representing Typical Turbine Blade Internal Cooling Passages Using Transient Techniques , 1979 .

[12]  B. K. Hodge,et al.  A Re-Evaluation of Schlichting’s Surface Roughness Experiment , 1984 .

[13]  Steven A. Hippensteele,et al.  Use of a liquid-crystal and heater-element composite for quantitative, high-resolution heat-transfer coefficients on a turbine airfoil including turbulence and surface-roughness effects , 1987 .

[14]  D. Dipprey,et al.  An experimental investigation of heat and momentum transfer in smooth and rough tubes at various Prandtl numbers , 1961 .

[15]  B. K. Hodge,et al.  Prediction of Turbulent Rough-Wall Skin Friction Using a Discrete Element Approach , 1985 .

[16]  D. Metzger,et al.  Effects of Pin Shape and Array Orientation on Heat Transfer and Pressure Loss in Pin Fin Arrays , 1984 .