Scott K. Thomas and Richard C. Lykins

Department of Mechanical and Materials Engineering

Wright State University, Dayton, OH 45435-0001

and

Kirk L. Yerkes

Research Engineer

Air Force Research Laboratory (PRPG)

Wright-Patterson AFB, OH 45433-7251

This paper discusses the behavior of fully developed laminar flow of liquid along trapezoidal grooves. The conservation of mass and momentum equations reduce to the classic Poisson equation in terms of the liquid velocity. A finite difference solution was employed to determine the mean velocity, volumetric flow rate, and Poiseuille number (Po = fRe) as functions of the groove aspect ratio, groove-half angle, meniscus contact angle and imposed shear stress at the liquid-vapor interface. Comparisons with existing solutions for fully developed flow in rectangular ducts and rectangular and triangular grooves are provided. The volumetric flow rate in a groove in which the fill amount varies is discussed. A semi-analytical solution for the mean velocity in a groove is presented and used to determine the capillary limit for a revolving helically-grooved heat pipe.