Filling structure design and cooling mechanism study of the heat-not-burn cigarettes with sidewall openings

The smoke temperature of heat-not-burn cigarettes is usually high, which affects the user experience. This study investigates the application of filled structures in the cooling process of heat-not-burn cigarette smoke through experiments and numerical simulations. A cigarette structure that can effectively reduce the smoke temperature is identified. The temperature distribution characteristics and flow process of heat-not-burn cigarettes with straight and filled multifluid structures were investigated by numerical simulation. The mixing mechanism between high-temperature smoke and air inside them was revealed. The low-temperature air and high-temperature smoke are centrally mixed in the straight structure and are concentrated in the center of the structure under the effect of shear flow. In the multi-flow channel structure, the low-temperature air and high-temperature smoke diffuse to the wall due to the structural inflow and the pressure in the center return area, which is the decentralized mixing mode. The decentralized mixing method can promote the mixing between low-temperature air and high-temperature smoke and effectively reduce the temperature of the smoke. It has a 7 K cooling effect on the smoke compared to the straight structure, which can provide a new solution for exploring healthier and superior heat-not-burn cigarettes.