| The National Aeronautical And Space Administration (NASA) Glenn Research Center at Lewis Field in Cleveland, Ohio, supports a research program called the Analysis of Thermo-diffusive and Hydrodynamic Instabilities in Near-extinction Atmospheres (ATHINA), which conducts studies of micro-gravity flame spread. This is an important research interest for NASA since it is related to NASA space mission safety. All of the NASA combustion and flame tests are performed in a drop tower, which creates a micro-gravity environment. However, the drop tower tests are expensive and there are severe time limitations on the resulting unstable flame from formation, or what is commonly known as flamelets formation.;To overcome the above limitations on the drop tower, a simulated micro-gravity device was constructed to perform flame instability transition and flame spread tests over thin cellulosic fuels. This device, called the Simulated Micro-gravity Flame Tunnel (SMFT), successfully simulates micro-gravity effects on combustion that are similar to those in the drop tower. The experimental results demonstrate that the process of flame change from the stable to the instable form is reversible. Also, for oxidizer flow velocities near the range that will produce flame instability, the flame spread velocity is highly influenced by the flame stability. This is not the case when the oxidizer flow velocities are in the higher values of their range. |
