Concurrent flow flame spread experiments are conducted over thermally thin solid fuels in microgravity aboard the International Space Station (ISS) under varying levels of confinement. Samples of cotton fiberglass blended textile fabric are burned in air flows in a small flow duct. Baffles are placed parallel to the sample sheet, one on each side symmetrically. The distance between the baffles is varied to change the confinement of the burning event. Three different materials of baffles are used to alter the radiative boundary conditions of the space that the flame resides: transparent polycarbonate, black anodized aluminum, and polished aluminum. In all tests, samples are ignited at the upstream leading edge and allowed to burn to completion. The results show that at low flow speeds (<17 cm/s), the flame reaches a steady state for all tested baffle types and baffle distances. The spread rates and flame lengths at the steady state increase first and then decrease when the baffle distance decreases, resulting in an optimal baffle distance for flame spread. Furthermore, there exists a limiting baffle distance below which the flame fails to spread. It is concluded that the confinement imposed by the baffles accelerates the flow during the combustion thermal expansion and the baffles reflect flame radiation back to the sample surface, both of which intensifying the burning. However, the confinement also limits the oxygen supply and introduces conductive heat loss away from the flame. At the same baffle distance and imposed flow speed, flame length and spread rate are largest for polished aluminum baffles, and lowest for transparent polycarbonate baffles. The differences are most prominent at intermediate tested baffle distances. While the radiative heat feedback from the baffles is expected to increase when the baffle distance decreases, flame length and flame spread rate are similar for all baffle types at small baffle distances as the combustion is limited by the reduced oxygen supply.

在国际空间站（ISS）上的微重力下，对热稀薄的固体燃料在不同的限制水平下进行并流火焰扩散实验。棉玻璃纤维混纺织物的样品在小气流管道中的气流中燃烧。挡板平行于样品板放置，每侧对称。挡板之间的距离是变化的，以改变燃烧事件的范围。三种不同的折流板材料用于改变火焰所在空间的辐射边界条件：透明聚碳酸酯，黑色阳极氧化铝和抛光铝。在所有测试中，样品在上游前沿点燃，并燃烧至完全。结果表明，在低流速（<17 cm / s）下，对于所有测试的挡板类型和挡板距离，火焰均达到稳定状态。稳定状态下的扩散速率和火焰长度先增大，然后随着挡板距离的减小而减小，从而为火焰扩散提供了最佳的挡板距离。此外，存在限制的挡板距离，在该距离以下火焰无法扩散。结论是，在燃烧热膨胀过程中，挡板施加的约束条件加速了流动，挡板将火焰辐射反射回样品表面，这两者都加剧了燃烧。但是，这种限制也限制了氧气的供应，并导致远离火焰的传导性热损失。在相同的挡板距离和施加的流速下，抛光铝挡板的火焰长度和扩散率最大，透明聚碳酸酯挡板的价格最低。差异在中间测试的挡板距离处最为明显。尽管当挡板距离减小时，来自挡板的辐射热反馈预计会增加，但是对于短挡板距离的所有挡板类型，火焰长度和火焰扩散速率都相似，因为燃烧受氧气供应减少的限制。