The virial expansion of the collective mobility ~sedimentation! coefficient is considered for hard sphere suspensions at equilibrium. The term of the second order in volume fraction, which involves three-particle hydrodynamic interactions, is calculated with high accuracy. To achieve that we represent the collective mobility coefficient as the sum of convergent integrals over particle configura...

this paper presents the application of the generalized differential quadrature (gdq) method for the hydrodynamic analysis of circular and noncircular, two lobe and three lobe, journal bearings. gdq is a simple, efficient, high-order numerical technique and it uses the information on all grid points to approach the derivatives of the unknown function. the effectiveness of the solution technique ...

We calculate the average hydrodynamic stress on fractal aggregates of spheres using Stokesian dynamics. We find that for fractal aggregates of force-free particles, the stress does not grow as the cube of the radius of gyration, but rather as the number of particles in the aggregate. This behavior is only found for random aggregates of force-free particles held together by hydrodynamic lubricat...

We use shear-reversal simulations to explore the rheology of dense, non-Brownian, noninertial, suspensions, resolving lubrication forces between neighboring particles and modeling particle surface contacts. The transient stress response to an abrupt reversal of the direction of shear shows rate-independent, nonmonotonic behavior, capturing the salient features of the corresponding classical exp...

Extreme hydrodynamic events such as hurricanes or tsunamis threaten coastal regions in particular. Such hazards must be assessed and appropriately incorporated into building codes to mitigate casualties damages structures. Guidelines are often developed through experimental investigations that assume buildings remain rigid during loading. To challenge this ‘rigid paradigm’, test specimens were ...

This paper presents a complete derivation and design of physics-informed neural network (PINN) applicable to solve initial boundary value problems described by linear ordinary differential equations. The objective with this technical note is not develop numerical solution procedure which more accurate efficient than standard finite element- or difference-based methods, but give fully explicit m...

Mechanical engineering often uses fluid lubrication to limit friction. Even in the presence of a lubricant, metallic contact between the sliding surfaces may readily occur. In running-in, the oil film thickness can be so thin that contact arises at the summit of asperities, thus, increasing both the friction coefficient and wear. Such regimes are the so-called mixed or boundary lubrication. In ...

Hydrodynamic and aerodynamic lubrication regimes in their controllable forms have been intensively investigated over the last two decades. With the aim of reducing friction and improving thermal, static, and dynamic characteristics of radial sliding bearings, different types of electro-mechanical actuators have been coupled to such bearings. Depending on (i) the actuator type; (ii) the actuatio...

A previously developed mesoscopic friction model for glass/PP textile composite laminates during forming is evaluated for glass and carbon/PPS laminates, at higher temperatures and lower viscosities than before. Experiments were performed for tool/ply and ply/ply configurations in a new friction test set-up. The experimental results indicate that this contact is indeed in the hydrodynamic regim...