We prove null controllability for linear and semilinear heat equations with dynamic boundary conditions of surface diffusion type. The results are based on a new Carleman estimate for this type of boundary conditions.

In order to make the prediction of land surface heat fluxes more robust, two improvements were made to an operational two-layer model proposed previously by Zhang. These improvements are: 1) a surface energy balance method is used to determine the theoretical boundary lines (namely 'true wet/cool edge' and 'true dry/warm edge' in the trapezoid) in the scatter plot for the surface temperature ve...

The mechanism behind the collapse of turbulence in the evening as a precursor to the onset of the very stable boundary layer is investigated. To this end a cooled, pressure-driven flow is investigated by means of a local similarity model. Simulations reveal a temporary collapse of turbulence whenever the surface heat extraction, expressed in its nondimensional form h/L, exceeds a critical value...

To determine the deformation of a body from the system of differential equations governing its thermo-mechanical deformations, we need side conditions such as boundary conditions. The most frequently employed boundary conditions are those of place and/or traction in a purely mechanical problem and of temperature and/or heat flux in a thermal problem. These and other more familiar mechanical bou...

the aim of this paper is to enhance thermal performance of a microchannel heat sink by using nanoencapsulated phase change material (nepcm) slurry as a cooling fluid instead of pure fluid. a threedimensional model of a circular channel using water slurry of nepcm was developed. the results show a significant reduction in the mean fluid temperature along the channel and heat sink wall temperatu...

A = hole surface Ma = Mach number Re = Reynolds number reff = effective hole radius rmod = modified hole radius q = heat flux at the wall T = temperature T = spanwise mean temperature u, v, w = velocity in x, y and z direction x = downstream coordinate y = wall-normal coordinate z = spanwise coordinate = boundary-layer thickness = emission coefficient = cooling effectiveness = spanwise mean coo...

this article investigates the nonlinear, steady boundary layer flow and heat transfer of an incompressible eyring-powell non-newtonian fluid from an isothermal sphere with biot number effects. the transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a second-order accurate implicit finite-difference keller box technique. the influ...