As a result by comparison with smooth substrates, which exhibited fouling within a day, very rough (roughness ratio >2.7) surfaces exhibited high resistance to fouling over a 6-month period.
With increasing long wavelength roughness ratio σ/ξ, the ratio between the measured and the actual interface stress decreases.
The increase in the heating surface area due to the roughness ratio improves nucleate BHT due to the enhancement of convective heat transfer.
The roughness ratio, r, is a measure of how surface roughness affects a homogeneous surface.
The roughness ratio is defined as the ratio of true area of the solid surface to the apparent area.
This heterogeneous surface, like that seen in Figure 8, is explained using the Cassie Baxter equation (Cassie's law): :\cos\,{\theta^*}= r_{f}\,f \,\cos\,{\theta_\text{Y}}+f-1 Here the rf is the roughness ratio of the wet surface area and f is the fraction of solid surface area wet by the liquid.
When Ra, total (nano-roughness + micro-roughness) exceeds 450 nm, WCA is greater than 154°, independent of the nano/micro-roughness ratio (RRNM).
The relationship between aero-damping ratio and reduced wind velocity (Vr), wind field roughness, aspect ratio, structural mass, structural damping as well as across-wind displacement was investigated systematically.
The model accepts surface roughness, gear ratio, horsepower and the number of teeth as input variables, and outputs calculated pinion surface asperity temperatures.
Experimental results of MCP of silicon wafers have achieved the average of surface roughness improvement ratio (SRIR) to 99% and the surface roughness Ra=0.633 nm measured by atomic force microscope (AFM).
