A detailed description is given of double burner fire whirls that are similar in structure to the type of combined whirls seen in nature. The whirls are generated using the fixed frame method, and two burners are placed symmetrically about the center of the fixed frame. The flame from each burner sweeps along the ground until it reaches the point midway between the burners, where the two flames wrap around each other in rotation as they stretch vertically. Stereo Particle Image Velocimetry is used to examine the structure and behavior of the whirls under different burner separation and burning rate conditions. The circulation, Froude number and whirl height for the double burner whirls are found to follow similar scaling relationships to those found for single centered and offset burner whirls, but the velocity profiles display significant differences, including the presence of lobed radial velocity profiles in the core of the combined whirl. The air entrainment contours suggest double whirls may be more effective at entraining, lifting, and ejecting flaming debris.

详细描述了双燃烧器火漩涡，其结构类似于自然界中所见的组合漩涡类型。使用固定框架方法产生涡流，两个燃烧器围绕固定框架的中心对称放置。来自每个燃烧器的火焰沿着地面扫过，直到它到达燃烧器之间的中间点，在那里两个火焰在垂直伸展时相互缠绕旋转。立体粒子图像测速法用于检查在不同燃烧器间距和燃烧速率条件下的涡流结构和行为。发现双燃烧器涡流的循环、弗劳德数和涡流高度遵循与单中心和偏置燃烧器涡流相似的比例关系，但速度剖面显示出显着差异，包括在组合涡旋的核心中存在瓣状径向速度剖面。空气夹带轮廓表明双旋风在夹带、提升和喷射燃烧的碎片方面可能更有效。