Elastoconstriction resistance

Elastoconstriction resistance and gap and joint resistances for line and point contacts are presented. Contact conductances of conforming rough surfaces that undergo (1) elastic, (2)... 

The contact resistance of the sphere-flat contact shown in Fig. 3.23 is discussed in this section. The thermal conductivities of the sphere and flux tube are /c, and k2, respectively. The total contact resistance is the sum of the constriction resistance in the sphere and the spreading resistance within the flux tube. The contact radius a is much smaller than the sphere diameter D and the tube diameter. Assuming isothermal contact area, the general elastoconstriction resistance model [143] becomes ... 

Elastoconstriction Resistance of Cylinder-Flat Contacts. The thermal contact resistance model for the contact formed by a smooth circular cylinder of diameter D and thermal conductivity ku and a smooth flat of thermal conductivity k2, was reported by McGee et al. [63] to be... 

Experimental Verification of Elastoconstriction and Elastogap Models. Experimental data have been obtained for the elastoconstriction resistance of point contacts [47] and line contacts [63] for a range of sphere and cylinder diameters, material properties, and mechanical loads. Data were obtained for the verification of the elastogap model for the point contact [46] and line contact [63]. The elastogap models have been tested with air, argon, helium, and nitrogen as the gap fluid at gas pressures from 10"6 torr to atmospheric pressure. 

Some representative test data for the elastoconstriction and elastogap resistances compared with the theoretical values are given in the following sections. 

The radiative resistance was approximately 10 times the constriction resistance at the lightest load and 30 times at the highest load. The largest difference between the theory and experiments is approximately -4.7 percent, within the probable experimental error. These and other vacuum tests [47] verified the accuracy of the elastoconstriction and the radiation models. 

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