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Showing papers on "Slip ratio published in 1977"


Journal ArticleDOI
15 Mar 1977
TL;DR: In this paper, a slip velocity at the contact line of a liquid drop on a solid surface originates because of the force induced by the gradient of the chemical potential in the liquid along the solid-liquid interface.
Abstract: A slip velocity at the contact line of a liquid drop on a solid surface originates because of the force induced by the gradient of the chemical potential in the liquid along the solid-liquid interface. Einstein's equation is used to relate the slip velocity and the force. The gradient occurs because (a) the interaction potential at the liquid-solid interface near the contact line due to the neighboring molecules differs from that of a semi-infinite liquid and depends upon the distance from the contact line and (b) the chemical potential is pressure dependent.

120 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the effect of wall slip during the capillary flow of polymer melt for low and high density polyethylene and found that wall slip occurs in both cases, and that the effect is related to melt fracture.
Abstract: The phenomenon of wall slip during the capillary flow of polymer melt is investigated for low and high density polyethylene. It is found that wall slip occurs in both cases, and that the effect is related to melt fracture. In addition, it is shown that a silicone fluid exhibits wall slip. The performance of the metering zone of a 38 mm diameter single-screw extruder is discussed in relation to wall slip. It is suggested that the power consumption of the extruder is reduced as a result of slip at the polymer/metal interface. Results based on experiments with the silicone fluid tend to support this hypothesis. A theoretical analysis of the effects of wall slip upon throughput rate and power consumption for a one-dimensional isothermal Newtonian case is included.

37 citations



01 Oct 1977
TL;DR: In this article, an experimental investigation was conducted at the Langley aircraft landing loads and traction facility to study the braking and cornering response of a slip ratio controlled aircraft antiskid braking system with ground speed reference derived from an unbraked nose wheel.
Abstract: An experimental investigation was conducted at the Langley aircraft landing loads and traction facility to study the braking and cornering response of a slip ratio controlled aircraft antiskid braking system with ground speed reference derived from an unbraked nose wheel. The investigation, conducted on dry and wet runway surfaces, utilized one main gear wheel, brake, and tire assembly of a DC-9 series 10 airplane. During maximum braking, the average ratio of the drag force friction coefficient developed by the antiskid system to the maximum drag force friction coefficient available was higher on the dry surface than on damp and flooded surfaces, and was reduced with lighter vertical loads, higher yaw angles, and when new tire treads were replaced by worn treads. Similarly, the average ratio of side force friction coefficient developed by the tire under antiskid control to the maximum side force friction coefficient available to a freely rolling yawed tire decreased with increasing yaw angle, generally increased with ground speed, and decreased when tires with new treads were replaced by those with worn treads.

14 citations


Journal ArticleDOI
TL;DR: In this paper, an analytical method is proposed for the problem of rarefied gas channel flow, on the basis of the concept of locally-uniform velocity distribution, and the flow in a circular tube is analyzed.
Abstract: An analytical method is proposed for the problem of rarefied gas channel flow, on the basis of the concept of locally-uniform velocity distribution, and the flow in a circular tube is analyzed. The solution is in good agreement with the experimental results over the whole range of Knudsen number. From the derived results, a new expression of the slip coefficient is also proposed.

5 citations


Proceedings ArticleDOI
01 May 1977
TL;DR: In this paper, an aerodynamic isotope separation technique based on the velocity slip between gases in a rarefied flow has been proposed, and the velocity and translational temperature of the individual species in binary and ternary gas mixtures of argon and neon in helium have been studied in a low density hypersonic free jet.
Abstract: An aerodynamic isotope separation technique based on the velocity slip between gases in a rarefied flow has been proposed. To evaluate the efficiency of this separation technique, the velocity and translational temperature of the individual species in binary and ternary gas mixtures of argon and neon in helium have been studied in a low density hypersonic free jet. The velocity and temperature of the gas were determined from the Doppler shift and broadening of the fluorescence excited by an electron beam. Velocity slip and translational nonequilibrium were observed over a range of source pressures. A separation factor based on the velocity slip and temperatures was also determined. A comparison of the velocity slip, temperatures, and separation factor with the results of a Monte Carlo simulation of the flow field is presented.

3 citations


01 Jan 1977
TL;DR: The Argonne National Laboratory ambient-temperature NaK-nitrogen facility was recently rebuilt for tests at higher liquid velocities and pressures The revised facility is described Recent runs with the same parameters as with the old facility showed better generator operation was obtained--the slip ratio was lower and the power level was higher as mentioned in this paper.
Abstract: The Argonne National Laboratory ambient-temperature NaK-nitrogen facility was recently rebuilt for tests at higher liquid velocities and pressures The revised facility is described Recent runs with the same parameters as with the old facility showed better generator operation was obtained--the slip ratio was lower and the power level was higher Operation at higher liquid velocities showed still further reductions in slip ratio and increased generator efficiency The initial steps in a program to evaluate surface-active agents in the generator are described

2 citations