A theoretical model for axial capillary flow in rectangular microgrooves was presented with the assumptions that the meniscus radius in the cross section is approximately constant, and the height of the centerline film recedes along the axial direction with a convex form. Experimental data obtained by Micro-PIV verify the assumptions. Comparison with the experimental data shows that the model is accurate to predict the axial profile of the liquid film for inclined rectangular microgrooves.
A theoretical model is presented to better understand the axial capillary characteristics in rectangular microgrooves. The experimental data obtained by Micro-PIV verify the assumptions adopted in the model: the meniscus radius in any cross section is approximately constant; the height of the centerline film recedes along the axial direction with a convex form but not a concave form. Reasonable assumptions promote accuracy of the theoretical model, and it is applicable and accurate to predict the axial profile of the liquid film for inclined rectangular grooves. The investigations show that the wetting length is mainly determined by the contact angle (a), the groove dimension and the minimum radius of the groove corner (rmin). In the case of low heat input or large tilt angle, the axial flow is mainly controlled by the gravitational force, and the groove depth has little effect on the accommodation length.
The results have been published on EXPERIMENTAL THERMAL AND FLUID SCIENCE Volume: 60 Pages: 241-251
Schematic of the considered microgroove in the model