Temperature Patterns of Air Crossflow with Hollow-Cone Spray Evaporation

This work focused on the heat transfer of the mixing process resulting from a hollow-cone spray evaporation in high-temperature gas crossflow in a confined mixing space. The study was carried out in a rectangular duct with a cross-sectional area of 95 x 95 mm. The temperatures on four cross sections (45 measuring points on half of a cross section) of crossflow were measured using thermocouples. The temperature pattern of gas crossflow caused by the evaporation of hollow-cone spray was obtained, and the effects of factors such as crossflow velocity, crossflow temperature, spray droplet size, and spray injection angle on the temperature pattern were investigated. The main findings of this study were as follows: 1) The polydispersed hollow-cone spray droplets and the droplet-wall impingement made the heat transfer on the cross section of the flowfield inherently nonuniform. 2) The mixing flowfield fell into five regions characterized by different heat transfer mechanisms. 3) The temperature pattern of crossflow was significantly affected by the spray injection angle. 4) A good mixing between hollow-cone spray and high-temperature crossflow could only be achieved with a proper spray penetration depth.