This paper presents a one-dimensional, semi-analytical model for prediction of the wetted length supported by inclined triangular capillary grooves subject to heating from below. The model utilizes a macroscopic approach employing the concept of an apparent contact angle. Constant liquid properties are assumed and no specific account is taken of surface roughness. The concept of accommodation theory is introduced to account for the change in the radius of curvature of the liquid-vapor interface between the liquid reservoir and the groove proper. Empirical input is required in the form of the axial heat flux profile and the axial profile of the liquid height in the groove. To assist other researchers in the implementation of the model, this paper concludes with a series of design curves. These curves can readily be used to estimate the wetted length (capillary limit) in inclined heated triangular capillary grooves for a variety of operating conditions.

Issue Section:
Heat Pipes
Keywords:
Evaporation, Heat Transfer, Heat Pipes, Thin Films, wetting, contact angle, heat transfer, evaporation, confined flow
Topics:
Design, Evaporation, Flow (Dynamics), Geometry, Gravity (Force), Heat flux, Heat transfer, Reservoirs, Thin films, Vapors, Heat pipes, Friction, Heating, Surface roughness
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Copyright © 2002
 by ASME
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