Figure 1 (IMAGE) Tohoku University Caption The relationships between distance from inlet boundary and inlet velocity for stoichiometric methane-air mixtures. The open circle-shaped markers mean that the inlet velocity is the same with the velocity of the deflagration wave. The open star-shaped markers mean that the inlet velocity is the same with the velocity of the detonation wave. The open diamond-shaped markers mean that the velocity can exceed the speed of sound within the reaction wave when the inlet velocity is subsonic. Credit Youhi Morii Usage Restrictions Reporters may use freely these materials in news coverage with appropriate credit information. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.