Design, Manufacturing and Assessment of Ignition Delay Time System Based on Drop Test Method

One of the properties for liquid bipropellants is their hypergolicity. The required quantity for this purpose is ignition delay time (IDT). IDT is classified into two classes: physical and chemical. The chemical ignition delay time is the time interval between the contact of fuel droplet - oxidizer surface and appearance of the first flame. The most appropriate laboratory method for measuring the chemical ignition delay time is drop test. Considering the effective parameters on the ignition delay time (such as oxidizer to fuel ratio, temperature and pressure) and following the mechanical design, this system was manufactured with capability of temperature and the reaction chamber pressure adjustments. For calibration and standardization of the system, some liquid fuels (such as triethyl amine, unsymmetrical dimethyl hydrazine and Tonka-250 mixture) and some liquid oxidizers (such as strong nitric acid and conventional oxidizer AK27) were applied. Good repeatability and dispersity of the obtained results indicate the system accuracy.