Abstract: In order to study the variation trend of n?heptane flame shape, flame brightness and flame temperature over time, the combustion experiments of n?heptane were carried out with the inclined plane devices of 25° and 40° respectively. The results show that under the two inclined planes, the inertia of the hot and cold air in the box is different due to the different density, which causes the uneven temperature distribution inside the box to produce pressure difference, and the flame tilts to the slide direction of the box under the action of pressure difference. Under the comprehensive influence of vertical and horizontal acceleration, the length, inclination and height of the flame are shortened, but the brightness is enhanced, and the increasing inclination of the inclined plane will have a greater impact on its shape and brightness. The flame shape parameter values at 40° inclined plane are 6.21%, 12.30% and 6.72% lower than those at 25° inclined plane, respectively. However, the flame brightness is 31.98% higher than that of 25° inclined plane. In addition, the temperature of the n?heptane flame decreased due to instability during the sliding process, and the flame temperature at 40° and 25° inclined plane decreased by 16.05% and 22.22%, respectively. However, the flame temperature at 40° inclined plane is higher than that at 25° inclined plane, which is related to the weakening of buoyancy effect caused by the decrease of vertical acceleration.

Key words: slope slide, flame morphology, flame brightness, flame temperature