We calculate the ionisation fraction in protostellar disk models using two different gas–phase chemical networks, and examine the effect of turbulent mixing by modelling the diffusion of chemical species vertically through the disk. The aim is to determine in which regions of the disk gas can couple to a magnetic field and sustain MHD turbulence. The disk models are conventional α–disks, and th...

The purpose of this study is to investigate the effect of radiation heat transfer on temperature distribution and heat flux to the walls of a diesel engine. A diffusion flame is modeled in a simple cylindrical geometry and boundary conditions are defined. A specific solver which can model the turbulent diffusion flame by considering radiation in participating media is used to solve the problem....

The process of particle cross-field diffusion in high amplitude Alfvénic turbulence is considered using the method of the Monte Carlo particle simulations. We derive the cross-field diffusion coefficient κ⊥ and the parallel diffusion coefficient κ‖ in the presence of different 1-D, 2-D and 3-D turbulent wave field models and discuss the κ⊥, κ‖ and κ⊥κ‖ variations with the wave amplitude. κ⊥ is ...

The phase transition for turbulent diffusion, reported by Avellaneda and Majda [Avellaneda, M. & Majda, A. J. (1994) Philos. Trans. R. Soc. London A 346, 205-233, and several earlier papers], is traced to a modeling assumption in which the energy spectrum of the turbulent fluid is singularly dependent on the viscosity in the inertial range. Phenomenological models of turbulence and intermittenc...

The role of magnetic fields for the formation of planets is reviewed. Protoplanetary disc turbulence driven by the magnetorotational instability has a huge influence on the early stages of planet formation. Small dust grains are transported both vertically and radially in the disc by turbulent diffusion, counteracting sedimentation to the mid-plane and transporting crystalline material from the...

The process of particle cross-field diffusion in high amplitude Alfvénic turbulence is considered using the method of the Monte Carlo particle simulations. We derive the crossfield diffusion coefficient κ⊥ and the parallel diffusion coefficient κ‖ in the presence of different 1-D, 2-D and 3-D turbulent wave field models and discuss the κ⊥,κ‖ and κ⊥κ‖ variations with the wave amplitude. κ⊥ is co...

For modeling exposure close to an indoor air pollution source, an isotropic turbulent diffusion coefficient is used to represent the average spread of emissions. However, its magnitude indoors has been difficult to assess experimentally due to limitations in the number of monitors available. We used 30-37 real-time monitors to simultaneously measure CO at different angles and distances from a c...

In 1979, Professor Bilger was among the first faculty to have a sabbatical visit at the new Combustion Research Facility (CRF) at Sandia Laboratories, in Livermore, California. During this sabbatical, Professor Bilger received from Dr. Mike Drake, then at General Electric Corporate Research and Development, an advance copy of the pioneering paper of Raman scattering in a turbulent flame of H2 i...