Liquid crystal methods for studying turbulent heat transfer

Abstract Liquid crystals that can accurately measure temperature and are relatively stable are now available. There are exciting new opportunities to apply these liquid crystals to the investigation of important and interesting heat transfer/fluid flow problems. Five methods of using narrow-band liquid crystals for the measurement of local heat transfer coefficients are reviewed in this paper. These methods have been developed and used at the University of California, Davis and include the heated-coating method, three variations of the transient method (preheated-wall transient, duct-insertion technique, and shroud-heating technique), and a uniform coating method. Some examples of applications for these methods are described. The examples include cylinders in cross-flow, pin fins, impinging jets, turbine blades, smooth and ribbed square ducts, and spirally fluted ducts.

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

[2]  A comparison of the transient and heated-coating methods for the measurement of local heat transfer coefficients on a pin fin , 1989 .

[3]  D. E. Metzger,et al.  Use of Melting Point Surface Coatings for Local Convection Heat Transfer Measurements in Rectangular Channel Flows With 90-deg Turns , 1984 .

[4]  T. V. Jones,et al.  Heat-transfer measurements in short-duration hypersonic facilities , 1973 .

[5]  J. Baughn,et al.  An Insertion Technique Using the Transient Method with Liquid Crystals For Enhanced Heat Transfer Measurements in Ducts , 1994 .

[6]  H. Merte,et al.  Semi-Transparent Gold Film as Simultaneous Surface Heater and Resistance Thermometer for Nucleate Boiling Studies , 1981 .

[7]  James W. Baughn,et al.  Heat transfer to air from a yawed cylinder , 1982 .

[8]  Terry V. Jones,et al.  An Advanced Method of Processing Liquid Crystal Video Signals From Transient Heat Transfer Experiments , 1993 .

[9]  S. A. Hippensteele,et al.  Evaluation of a Hue Capturing Based Transient Liquid Crystal Method for High-Resolution Mapping of Convective Heat Transfer on Curved Surfaces , 1993 .

[10]  Y. W. Kim,et al.  SIMULTANEOUS MEASUREMENT OF SURFACE TEMPERATURE AND HEAT FLUX USING A COMPOSITE SLAB , 1995 .

[11]  R. Takahashi,et al.  Local Heat Transfer Measurements Using an Electrically Heated Thin Gold-Coated Plastic Sheet , 1985 .

[12]  H. Iacovides,et al.  Local Heat Transfer Measurements in Turbulent Flow Around a 180-deg Pipe Bend , 1987 .

[13]  Terry V. Jones,et al.  The measurement of local heat transfer coefficients in blade cooling geometries , 1985 .

[14]  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 .

[15]  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 .

[16]  L. M. Russell,et al.  Local heat-transfer measurements on a large scale-model turbine blade airfoil using a composite of a heater element and liquid crystals , 1985 .

[17]  James W. Baughn,et al.  An Experimental Investigation of Heat Transfer, Transition and Separation on Turbine Blades at Low Reynolds Number and High Turbulence Intensity. , 1995 .

[18]  J. Simonich,et al.  New technique for mapping heat‐transfer coefficient contours , 1982 .

[19]  D. E. Metzger,et al.  Transient Liquid Crystal Measurement of Local Heat Transfer on a Rotating Disk With Jet Impingement , 1991 .

[20]  Validation of an in situ heated transient technique for local heat transfer measurements using a cylinder in crossflow , 1994 .

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

[22]  Liquid-crystal transient technique for measurement of in-tube local condensing heat transfer coefficients , 1995 .

[23]  T. Kunugi,et al.  Improved Liquid-Crystal Thermometry Excluding Human Color Sensation , 1989 .

[24]  S. A. Hippensteele,et al.  A New Hue Capturing Technique for the Quantitative Interpretation of Liquid Crystal Images Used in Convective Heat Transfer Studies , 1991 .

[25]  James W. Baughn,et al.  Heat Transfer Measurements From a Surface With Uniform Heat Flux and an Impinging Jet , 1989 .

[26]  R. Butler,et al.  SHROUD TECHNIQUE USING THE TRANSIENT METHOD FOR LOCAL HEAT TRANSFER MEASUREMENTS , 1995 .

[27]  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 .

[28]  S. C. Arora,et al.  Application of the Transient Test Technique to Measure Local Heat Transfer Coefficients Associated With Augmented Airfoil Cooling Passages , 1987 .