in this paper, the effects of input temperature and compression ratio on the net output work and efficiency of the air standard cycles, i.e. atkinson cycle, diesel cycle and otto cycle are analyzed. we assumed that the compression and power processes are adiabatic and reversible and any convective, conductive and radiative heat transfer to cylinder wall during the heat rejection process may be ...

in this paper, the effects of baffle on thermal characteristics of combined convection-radiation heat transfer in laminar flow adjacent to an inclined backward facing step (bfs) in a horizontal duct are investigated. a baffle is mounted on the top wall of channel downstream side of step. in this study, the fluid is treated as a gray, absorbing, emitting and scattering medium; therefore, in the ...

We constructed hydrodynamical model atmospheres for mid M-type main-, as well as pre-main-sequence (PMS) objects. Despite the complex chemistry encountered in these cool atmospheres a reasonably accurate representation of the radiative transfer is possible, even in the context of time-dependent and three-dimensional models. The models provide detailed information about the morphology of M-type ...

Projected rotational velocities (vsini) have been measured for a sample of 145 stars with masses between 0.4 and >10 M⊙ (median mass 2.1 M⊙) located in the Orion star-forming complex. These measurements have been supplemented with data from the literature for Orion stars with masses as low as 0.1 M⊙. The primary finding from analysis of these data is that the upper envelope of the observed valu...

Improving heat transfer and performance in a radial, finned, shell and tube heat exchanger is studied in this study. According to the second law of thermodynamics, the most irreversibilities of convective heat transfer processes are due to fluid friction and heat transfer via finite temperature difference. Entransy dissipations are due to the irreversibilities of convective heat transfer. There...

A framework has been developed that brings together the important physical parameters and processes governing the vertical mass flux in deep convective clouds and their area cover. The main result is a simple relation for the cloud mass flux and area fraction in terms of the large-scale radiative cooling, environmental stratification, and the extent of lateral entrainment of the ambient air by ...

Recently, both Rennó and Ingersoll (1996, hereafter RI) and Emanuel and Bister (1996, hereafter EB) derive theoretical formulas for the convective available potential energy (CAPE), the fractional area covered by active updrafts, and the vertical velocity in the active updrafts for atmospheres in radiative–convective equilibrium. The theories of RI and EB differ primarily in the means of closur...