Effect of Surface Curvature on Contact Resistance between Abutting Cylinders
Abstract: Due to the
microscopic roughness of contacting materials, an additional thermal resistance arises
from the constriction and spreading of heat near contact spots. Predictive models for
contact resistance typically consider abutting semi-infinite cylinders subjected to an
adiabatic boundary condition along their outer radius. At the nominal plane of contact
an isothermal and circular ... read morecontact spot is surrounded by an adiabatic annulus and the
far-field boundary condition is constant heat flux. However, cylinders with flat bases
do not mimic the actual geometry of contacts. To remedy this, we perturb the geometry of
the problem such that, in cross section, the circular contact is surrounded by an
adiabatic arc. When the curvature of this arc is small, our solution is semi-analytical.
Then, we employ a series solution for leading-order (flat-base) problem and use Green's
Second Identity to compute the increase in contact resistance without needing to resolve
the temperature field. Complimentary numerical results for contact resistance span the
full range of geometric parameters, i.e., contact fraction and protrusion angle of the
arc. The results suggest as much as a 10-15% increase in contact resistance for
realistic contacts for typical contact sizes and asperity
Thesis (M.S.)--Tufts University, 2018.
Submitted to the Dept. of Mechanical Engineering.
Advisor: Marc Hodes.
Committee: Xiaozhe Hu, and Erica Kemmerling.
Keywords: Mechanical engineering, Low temperature physics, and Applied mathematics.read less