Due to the impracticality of performing material screening tests in space, NASA is seeking ways to conduct tests in normal gravity and relate test results to those in reduced gravity. One possible test for simulating low/zero gravity conditions is described. The difference between 1-g and μg is the buoyant plume. This apparatus, akin to a Hele-Shaw Cell in fluid dynamics, approximates μg convection by suppressing the vertical flow, forcing the flow stream-wise down the channel axis. Two test beds (at MSU, NASA) are used for tests with cellulose fuel for several opposed airflow rates. Flame spread rates agree well with data from the NASA Zero-g Facility for the same flow velocities. Details are explored how closely a narrow vertical channel apparatus can simulate 0-g conditions. A scaling analysis was carried out on the stream-wise (down-channel) and buoyant (vertical) flow, and the thermal expansion. Results include numerical predictions of the flow field and flame behavior using the FDS program for 1-g and 0-g conditions, flame spread rates measured with the apparatus both right-side up and upside down, and comparisons with 0-g measurements in a drop facility. The flame-spread tests have yielded 1-g and 0-g flammability maps that agree well. The implications of heat loss to the channel ceiling are discussed, also velocity gradient effects in the Narrow Channel (NC). Suggestions are made of other quantities that could be measured besides flame-spread rate.
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