Weak deflagration

Weak deflagration since 2 > Y (subsonic flow to subsonic) Strong deflagration since P2 < Py(ll/i2 > l/pY) (subsonic flow to supersonic)... 

Region III (weak deflagration) encompasses the laminar flame solutions that were treated in Chapter 4. 

Region IV p > pj subsonic flow to subsonic flow, weak deflagration... 

The other waves are classified as follows weak detonations, strong detons, weak deflagrations and strong deflagrations (Ref 38,... 

Region IV p2 > Pk subsonic flow to subsonic flow, weak deflagration Region V P2 < Tk supersonic flow to supersonic flow, strong deflagration... 

Classification Weak deflagration Chapman-Jouguet deflagration Strong deflagration Weak detonation Chapman-Jouguet detonation Strong detonation... 

The process from A to B is a weak deflagration, the type of combustion wave usually encountered. This combustion occurs at a rate which is governed to a large extent by the multiple diffusion processes within the neighborhood of the flame front. Such processes are leisurely and the propagation rates or flame speeds associated with such combustion are on the order of a few feet per second. 

Because of the large amount of heat release from combustion, gas explosions always involve high temperature rise. For example, the maximum flame temperatures for hydrogen and methane are 2045°C and 1875°C, respectively.f l Even for weak deflagrations in fuel-lean mixtures near the LFL, the flame temperatures of hydrocarbons are in the range of 1300-1350°C (p. 330 in Ref9 (). This is why even weak deflagrations such as flash fires can cause severe burn injuries. 

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