We discuss the phenomenon of physical aging in a well studied atomic model liquid, a binary mixture of particles interacting with Lennard-Jones potentials. We put emphasis on the different dynamical behaviours of the model as well as on the relations between the experimental and numerical timescales. The physics of aging is discussed within a well characterized thermodynamic framework, based on...

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The dynamics of bubble coalescence is studied using a robust numerical model for a multiphase flow system with interfaces. The effects of liquid viscosity and surface tension on bubble coalescence, for which Reynolds number ranges from 10 to 100 and Bond number ranges from 5 to 50, are investigated. It is shown that the numerical model used in this study can accurately capture the complex topol...

The colored ~Ornstein-Uhlenbeck! noise-driven nonequilibrium dynamics of massive damped Brownian particles in a periodic but asymmetric potential ~ratchet! is investigated. Our special focus is on the influence of inertia in the particle dynamics for the noise induced, directed current. By means of two approximation schemes ~a unified colored noise approximation and a path-integral approach! an...

We numerically study the influence of scattering along the channel and extension regions of dual gate nano-MOSFETs. It is found that the reduction in drain current due to scattering in the right half of the channel is comparable to the reduction in drain current due to scattering in the left half of the channel, when the channel length is comparable to the scattering length. As the channel leng...

The application of quasi-Newton methods is widespread in numerical optimization. Independently of the application, the techniques used to update the BFGS matrices seem to play an important role in the performance of the overall method. In this paper we address precisely this issue. We compare two implementations of the limited memory BFGS method for large-scale unconstrained problems. They diie...

An incompressible, reactive, viscous ow reaches a hot circular cylinder causing a reaction to start. We observe the progress of the reaction, concentrating in the transition towards turbulence within the boundary layer. The problem is divided into the uid dynamics eeects and the combustion eeects. The motion of the ow is resolved by the use of a hybrid vortex algorithm; the reactive part of the...

The focus of this work is the modeling and performance comparison of different models of pulse tube refrigerators, namely, the Orifice Pulse Tube Refrigerator (OPTR) and the Inertancetube Pulse Tube Refrigerator (IPTR) with both in-line as well as coaxial configurations. A detailed analysis of the flow and heat transfer in various components of the above mentioned models under oscillating flow ...