Detonation Characteristics of Gaseous Isopropyl Nitrate at High Concentrations

Isopropyl nitrate (IPN) is a component of propellant fuel. High concentrations of IPN can still produce detonation. To date, very limited literature is available regarding high concentrations of IPN detonations. The detonation pressure is related to the equivalence ratio and density of IPN/air mixtures. These two factors have opposing effects on the detonation of an IPN/air mixture. The detonation characteristics of gaseous IPN/air mixtures at high concentrations (300-4000 g/m³) have been studied numerically. The results showed that when the IPN concentration is 300-600 g/m³, density played a dominant role on detonation. The maximum detonation pressure, 2.81 MPa, and the maximum detonation velocity, 1890 m/s, occurred at a concentration of 600 g/m³ (equivalence ratio Φ = 2.15). When the IPN concentration was increased from 300 to 600 g/m³, the peak overpressure and velocity increased by 19.6% and 6.2%, respectively. When the IPN concentration is higher than 600 g/m³, the equivalence ratio is extremely large and the detonation properties were seriously degraded. An analysis of the detonation products illustrated the burn-off rate of high concentrations of IPN and the influence of the detonation product CH₃CHO. At a concentration of 600 g/m³, the IPN/air mixture can achieve optimal detonation properties and fuel economy.