Extreme weather often contributes to crown fires, where the fire spreads from one tree crown to the next as a series of piloted ignitions. An important aspect in predicting crown fires is understanding the ignition of fuel particles. The ignition criterion considered in this work is the critical mass flux criterion – that a sufficient amount of pyrolysis gases must be generated for a diffusion ...

in this study, mixed convection heat transfer and local and global entropy generation in aventilated square cavity have been investigated numerically. the natural convection effect isachieved by a constant heat flux imposed at the bottom wall and cooled by injecting a coldfollow. in order to investigate the effect of port location, four different placementconfigurations of the inlet and outlet ...

This paper presents the heat transfer coefficients and the pressure drop measured during HC-600a (Isobutane) condensation inside a brazed plate heat exchanger: the effects of saturation temperature, refrigerant mass flux and vapour super-heating are investigated. The heat transfer coefficients show weak sensitivity to saturation temperature and great sensitivity to refrigerant mass flux. At low...

We numerically investigate turbulent thermal convection driven by a horizontal surface of constant heat flux and compare the results with those of constant temperature. Below Ra≈ 10, where Ra is the Rayleigh number, when the flow is smooth and regular, the heat transport in the two cases is essentially the same. For Ra> 10 the heat transport for imposed heat flux is smaller than that for consta...

Due to the dependence of boiling heat transfer rate on heat flux, saturation pressure, mass flux and refrigerant quality, efforts made to increase heat transfer rate often cause further drop in refrigerant saturation pressure. In this study, entropy generation mechanisms associated with two-phase flow in smooth evaporator tube subject to constant surface heat flux are investigated. Refrigerant ...

In the current work optimization of double pipe fin-pin heat exchanger has been studied. The effective parameters those are controlling the heat exchanger performance are divided in two categories; geometrical and operating conditions. Using the Brent’s optimization algorithm and handling the thermodynamically design concept, one can minimize entropy generation in different length of heat excha...

In order to examine the laminar convective heat transfer of nanofluid, experiments carried out using silver-oil nanofluid in a concentric annulus with outer constant heat flux as boundary condition. Silver-oil nanofluid prepared by Electrical Explosion of Wire technique and observed no nanoparticles agglomeration during nanofluid preparation process and carried out experiments. The average size...

in the nighttime, drainage flow occurs along the basin sideslope and advects cold air to the boundary layer over the basin bottom (bbl), intensifying the cooling rate of the layer. a nocturnal cold air lake develops in the basin, attaining a depth nearly equal to the topographical depth of the basin. heat budget analysis of the whole basin surface shows that net radiative flux closely balances ...