Effect of Surface Texture

When nucleate boiling takes place on a hot solid, the surface texture of that solid becomes an important variable. A thorough study was made by Corty and Foust (C4), who boiled ether, pentane, and Freon-113 from horizontal, electrically heated copper and nickel surfaces. The surface texture was altered at will by use of different grades of emery polishing paper. 

The slopes of the boiling curves in Fig. 30 increase with increasing roughness. For the smooth metal the approximate relation is h = C(AT)li. For the roughest surface the exponent is 24. In no case did these experi- 

The authors explain their results in terms of gas-filled pits on the metal surfaces. It is argued that a fine polish results in pits of a narrow size range. The sizes are presumed to be such that a rather high superheat is required to get nucleation. The coarse finishes are presumed to give a wide range of pit sizes. Some pits will have the correct size to permit nucleation at a low superheat. 

Of course some increase in heat transfer should be expected with an increase in surface roughness just because of the surface-area increase. 

However, the increase in the total heat transfer is greater than can be accounted for by area considerations. Other observers report similar results. 

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Fig. 30. Effect of surface texture on nucleate boiling. Ether was boiled on a nickel plate polished with different grades of emery paper. The pressure was atmospheric. Typical data are given for one curve only (C4).

Fig. 31. Effect of surface texture. Roughness values were determined with a diamond-tipped profilometer. The data are from Fig. 30 (C4).

This now raises the issue of what is the correct value of the / c ratio for any given material. The CIE Technical Committee TC 1-28 published recommendations on how to handle various parameters that can affect the judgments of color differences as CIE Publication 101 [54]. In that study, the parameter that stood out was the effect of surface texture on the judgments of lightness differences. Small differences in lightness can be assessed for specimens with smooth glossy surfaces but not in samples with textured, patterned, or rough surfaces. Thus studies in the literature... 

Fio. 7. Effect of surface texture on transition boiling. Methanol was boiled at one atmosphere on a %-inch, horizontal, steam-heated, copper tube (D2). 

Flanagan, J.R. and Wing, A.M., Effects of surface texture and grip force on the discrimination of hand-held loads. Percept. Psychophys. 59 111-118,1997. 

The Effect of Surface Texture on the Friction of Automotive Interior Plastics... 

Hills, J.M. and Thomason, J.C. (1998) The effect of scales of surface roughness on the settlement of barnacle [Semibalanus balanoides) cyprids. Biofouling, 12, 57-69. Thomason, J.C., Letissier, M.D.A.A., Ocampo-Thomason, P., and Field, S.N. (2002) Optimising settlement tiles the effects of surface texture and energy, orientation and deployment duration... 

Giingdr, S., Edwards, L. Effect of surface texture on fatigue life in a squize-cast 6082 aluminium alloy. Fatigue Fract. Eng. Mater. Struct. 16(4), 391-403 (1993)... 

Mansell, M. and F. Rollet. 2009. The effect of surface texture on evaporation, infiltration and storage properties of paved surfaces. Water Sd. Technol. 60(1) 71-76. 

Zhao H, Park CK, Law KY (2012) Effect of surface texturing on superoleophohicity, contact angle hysteresis, and robustness . Langmuir 28 14925-14934... 

Effects of Surface Texture and Surface Roughness on Polymer Scratch Behavior... 

EFFECTS OF SURFACE TEXTURE AND SURFACE ROUGHNESS ON POLYMER SCRATCH... 

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