LAUSR

A new experimental method for evaluating the detonability of fuel–air mixtures (FAMs) based on measuring the deflagration-to-detonation (DDT) run-up distance and/or time in a standard pulse detonation tube (SDT) is used to rank gaseous premixed and non-premixed FAMs by their detonability under substantially identical thermodynamic and gasdynamic conditions. In the experiments, FAMs based on hydrogen, acetylene, ethylene, propylene, propane–butane, n-pentane, and natural gas of various compositions, as well as FAMs based on the gaseous pyrolysis products of polypropylene (PP), are used: from extremely fuel-lean to extremely fuel-rich at normal temperatures and pressures. The concept of equivalent FAMs exhibiting the same or similar detonability under the same conditions is proposed. Equivalent FAMs can be used for predictive physical modeling of detonation processes involving FAMs of other fuels. The ranking of FAMs in terms of their relative detonability allows choosing a propylene FAM for physical modeling of the operation process in the PP-fueled solid-fuel ramjets operating on detonative combustion.