... in a concentration of 50–200 mg/l was conducted. The prepared fuel blends in varying volume concentrations were tested on a four-ball tribotester. The effects of varying operating parameters such as load and temperature as well as oxidation of biodiesel fuel blend on friction and wear behavior were evaluated...

... that as the friction coefficient and mandrel angle increase the drawing force and induced stresses increase. However, the final tube thickness and length were found to decrease with an increase in both parameters. plastic deformation friction forming processes thin wall structures drawing (mechanical...

... reservoir pressure; an optimum area ratio for the gas/liquid pistons is approximately 40. The effect of friction in the pumping system was predicted to have a small effect on this optimum design. The results of this investigation will now be used to design and construct a prototype for field testing. 25...

... methods. Using a similar approach to that of Nikuradse the measured friction factor was related to the measured roughness values. Taking the value of the relative roughness and dividing it by the slope of the power spectrum of the measured roughness, a greatly improved fit with the measured friction...

...John R. Smith; Jeffrey B. Lund; Robert K. Galloway The impact of frictional forces on the overall forces when drilling with a PDC bit has previously been implied by models and by single cutter and bit tests. This report describes new experiments to measure friction between three different bit...

.... Frictional pressure drop measurements for upward vertical core flow in a 1-in. pipe, using a 17.6-Pa.s, 963-kg/m 3 oil and water at room temperature reported a decrease by over 1000-fold with respect to single-phase oil flow, being comparable to the flow of water alone in the pipe at mixture flow rate...

... and influx to main flow rate ratios ranging from 1/50 to 1/1000. For both the perforation and slot cases, three different completion densities and three different completion phasings are considered. Based on the experimental data, new friction factor correlations for horizontal well with multiple perforation...

...Alexander Martinez; Stefan Miska; Ergun Kuru; James Sorem, Mem. ASME In horizontal and extended reach drilling, a large frictional drag may occur. If the pipe buckles laterally or into a helical shape, additional lateral contact force, LCF, is developed between the pipe and the wellbore wall...