In this Letter, coalescence-bouncing transitions of head-on binary droplet collisions are predicted by a novel macroscopic model based entirely on fundamental laws of physics. By making use of the lubrication theory of Zhang and Law [Phys. Fluids 23, 042102 (2011)], we have modified the Navier-Stokes equations to accurately account for the rarefied nature of the interdroplet gas film. Through t...

Keeping up with the technological advances, turbomachinery industry aspires to integrate manufacturing, servicing and maintenance of their plants. Typically, these objectives may be accomplished by adoption of condition monitoring services and diagnostic solutions, resulting in improved plant operations, lower maintenance cost, and impart safety and reliability. Specifically, failure analysis, ...

This paper examines a number of practical questions about the possibility of using water mist to mitigate explosion hazards in some industrial applications. Water mist systems have been installed to replace Halon 1301 in gas compressor modules on Alaska’s North Slope oil fields. The hazard in the compressor modules includes fire in lubrication oil lines for the gas turbines that drive the compr...

Marangoni and thermocapillary driven systems represent two classes of flows in which the variation in surface tension at the gas-liquid interface can generate spontaneously spreading films. This article considers the linear stability of such flows within the lubrication approximation. Since the base state or unperturbed solutions in both cases involve spatially inhomogeneous profiles, the linea...

It is proposed to use elastomeric composites as artificial joint bearing surfaces to increase their fluid film lubrication and therefore reduce the number of failures which have been attributed to wear mechanisms related to frictional forces. The fluid generated between the surfaces supports part of the load and prevents direct contact of the bearing surfaces. In order to obtain optimum elastoh...

One of the advanced technologies incorporated into a micro gas turbine (MGT) is the dynamic air-lubricated (no oil lubrication) bearing. We investigated the performance characteristics of a self-acting air-lubricated bearing in a 50-kWe MGT. From the results of our experiments, we were able to clarify the following. (1) The thrust load of 300 N incurred by a 50kWe MGT cannot be supported by the...

BACKGROUND Following various types of naturally-occurring traumatic injury to an articular joint, the lubricating ability of synovial fluid is impaired, with a correlated alteration in the concentration and/or structure of lubricant molecules, hyaluronan and proteoglycan-4. However, the effect of arthroscopic cartilage repair surgery on synovial fluid lubricant function and composition is unkno...

This paper presents the effect of preload on static and dynamic performance characteristics of several gas-lubricated noncircular journal bearing configurations. The linearized system approach using finite element method is used to obtain both steady state and dynamic characteristics. The results of the investigation shows that preload has a significant effect on frictional power loss and the ...

We propose a simple model, supported by contact-dynamics simulations as well as rheology and friction measurements, that links the transition from continuous to discontinuous shear-thickening in dense granular pastes to distinct lubrication regimes in the particle contacts. We identify a local Sommerfeld number that determines the transition from Newtonian to shear-thickening flows, and then sh...

We propose a simple model, supported by contact-dynamics simulations as well as rheology and friction measurements, that links the transition from continuous to discontinuous shear thickening in dense granular pastes to distinct lubrication regimes in the particle contacts. We identify a local Sommerfeld number that determines the transition from Newtonian to shear-thickening flows, and then sh...