Air movement and heat loss from sheep. I. Boundary layer insulation of a model sheep, with and whoitut fleece
نویسنده
چکیده
A model sheep, made from metal cylinders and hemispheres, was heated electrically. Heat loss by forced convection in a wind tunnel was analysed in terms of the dependence of the Nusselt number (Nu) on Reynolds number (Re). For a bare trunk Nu = 0.095 J?e0-684, but with fleece covering the trunk to a depth of 3.5 cm, Nu = 0.0112 °-875 when the mean radiative temperature of the coat was taken as the surface tempera ture. Heat transfer by convection from the whole body, including legs, was described by Nu = 0.029 Re° -80. However, a bulk Nusselt number should not be used to estimate heat loss from a live sheep in a hot environ ment if the windspeed is below about 4 m s_1 because the relation between mean surface temperature, Nusselt number and convective heat flux is not unique.
منابع مشابه
Air movement and heat loss from sheep. I. Boundary layer insulation of a model sheep, with and without fleece.
A model sheep, made from metal cylinders and hemispheres, was heated electrically. Heat loss by forced convection in a wind tunnel was analysed in terms of the dependence of the Nusselt number (Nu) on Reynolds number (Re). For a bare trunk Nu = 0.095 Re0.684, but with fleece covering the trunk to a depth of 3.5 cm, Nu = 0.0112 Re0.875 when the mean radiative temperature of the the coat was take...
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