Direct numerical simulations are used to investigate the method of film cooling in a laminar flat-plate Mach-2.67 boundary layer. Air is employed as mean-flow and coolant gas and is introduced into the boundary layer through one row of holes by means of a modeled blowing approach. The effects of a favorable streamwise pressure gradient are investigated for two different blowing rates and an adi...

A new finite volume algorithm has been developed to solve a variety of flows by using large eddy simulation and direct numerical simulation. This finite volume algorithm was developed using a dual time stepping approach with a preconditioning technique and a new factorization implementation. The method takes the advantage of pressure-based and density-based meth­ ods. Thus, it provides an effic...

Thin liquid wall fillTIs flowing under the influence of high-velocity turbulent gas streaIllS were studied for the purpose of obtaining an understanding of the Illechanics of filIll cooling. Conditions which insure liquid-filIll attachIllent to solid surfaces without loss of unevaporated liquid to the gas streaIll when siIllple radial-hole injectors are used were found; the IllaxiIlluIll allowa...

1 Contact author e-mail: [email protected] ABSTRACT A 3D electrothermal model is used to simulate and optimize Si/SiGe superlattice heterostructure micro-coolers. The model considers thermoelectric/thermionic cooling, heat conduction and Joule heating. It also includes non-ideal effects, such as contact resistance between metal and semiconductor, substrate/heatsink thermal resistance, the side c...

The solidification of two-dimensional liquid silicon confined to a slit nanopore has been studied using molecular dynamics simulations. The results clearly show that the system undergoes an obvious transition from liquid to multilayer hexagonal film with the decrease of temperature, accompanied by dramatic change in potential energy, atomic volume, coordination number and lateral radial distrib...

An analytical model has been developed for the study of turbulent film condensation from downward flowing vapors onto a horizontal elliptical tube with variable wall temperature. The interfacial shear at the vapor condensate film is evaluated with the help of Colburn analogy. The condensate film flow and local/or mean heat transfer characteristics from a horizontal elliptical tube with nonunifo...

Film-cooling flows are characterized by a row of jets injected at an angle from the blade surface or endwalls into the heated crossflow. The resulting flowfield is quite complex, and accurate predictions of the flow and heat transfer have been difficult to obtain using traditional two-equation turbulence models employed with ReynoldsAveraged Navier–Stokes (RANS) solvers. Recently, a four-equati...

Understanding metal alloy migration in metal-catalyzed nanowires growth is a prerequisite for improving its potential applications in the field of nanodevices. Here, we explored the surface migration of Au alloys in vertically aligned Si nanowires with different cooling rates. We varied the diameter of Au alloys by controlling the thickness of Au film as a catalyst for SiNW growth, and found th...

Superlattice material technologies in the Bi2Te3-material system can potentially enable efficient micro-scale thermoelectric devices for energy harvesting and active site-specific thermal management from ~200K to ~400K. The state-of-the-art in these thin film materials and the state of transition of these materials into device prototypes are presented. In the energy harvesting area, early resul...