Abstract: This paper presents the results of an experimental examination of the effect of non-uniform wall temperature on local heat transfer coefficient in a rotating smooth-walled square channel. Three different thermal boundary situations were investigated: (a) even and odd (four) wall uniform temperature, (b) even and odd (four) wall uniform heat flux, and (c) even (leading and trailing) w...

This paper focuses on building dynamic mathematical model of biomass boiler of medium energy output (in units of MW) as a controlled system and the use of this model in practice. Model of controlled system will serve especially for research of new ways of industrial biomass boilers control and will provide a device for the optimisation of existing control systems. At first, area of automatic co...

Fins are protrusions on a heat transfer surface to augment heat transfer rate from it. The increase in area exposed to convection in case of finned surfaces results in increased heat transfer rate. In this study heat transfer characteristics of a pin fin with perforation is numerically analyzed. A pin fin is fabricated and experiments are done under forced convection conditions. The experimenta...

This paper considers the problem of studying heat transfer exchange during boiling in a direct-flow recycling boiler using an organic coolant. The study was conducted numerical modelling ANSYS software package. Asaresultofthestudyavisual picture eofvaporphasedistributionwasobtained. shows that studied heat-exchange surface can be conditionally divided into two areas: area intense vaporization a...

In this paper, overall heat transfer coefficient and friction factor of water based γ-Al2O3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. For better dispersion of γ-Al2O3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kW and frequency of 35 kHz) were implemented. The stabi...

Direct burning is the most familiar way of producing energy from wood. Forest products industries are the main users of wood as fuel on a large scale, because they have much woody debris left over from milling and harvesting. The basic strategy is to reduce leftover wood to walnut-size or smaller particles. This size reduction is usually done by a "hog." Large pieces enter the top of the hog an...

in this paper, turbulent mixed convective heat transfer of water and al2o3 nanofluid has been numerically studied in a horizontal tube under non-uniform heat flux on the upper wall and insulation in the lower wall using mixture model. for the discretization of governing equations, the second-order upstream difference scheme and finite volume method were used. the coupling of pressure and veloci...

in this paper, overall heat transfer coefficient and friction factor of water based γ-al2o3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. for better dispersion of γ-al2o3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kw and frequency of 35 khz) were implemented. the stabi...