Transient and Steady-State Heat Transfer in Irradiated Citrus Fruit

This paper presents an analytical study of the thermal structure within citrus fruits that are artificially heated by radiant orchard heaters; this analysis may be utilized to establish more firmly orchard heating-design criteria. Transient and steady-state temperature solutions are derived for an ideal heat-transfer system consisting of a homogeneous sphere which suddenly receives radiant energy from a point source and loses energy by convection and reradiation to the surroundings. These solutions are compared to a set of experimental temperature measurements within an orange which was transiently irradiated in an orchard.