Suppression of Hard Start for Nontoxic Hypergolic Thruster Using H2O2 Oxidizer

Abstract

The present paper describes the phenomenon of hard start observed from a demonstrator of 500 N scale nontoxic hypergolic thruster using high-test peroxide as an oxidizer. When 90% concentration of hydrogen peroxide was used, the hard start was observed even under the fuel lead operation. To effectively suppress the occurrence of hard start phenomena in the startup phase of the thruster, oxidizer-to-fuel mass ratio and concentration of hydrogen peroxide have been individually considered. In drop tests, the ignition delays of hypergolic reactions became longer in the oxidizer-rich condition than those measured in the fuel-rich condition. By regulating oxidizer-to-fuel mass ratio with deliberate control of the oxidizer mass flow rate, the thruster operated smoothly even using 90% high-test peroxide in the fuel-rich environment. Furthermore, without the utilization of the flow control device, the thruster successfully operated when higher concentrations of high-test peroxide (95 and 98%) were used under the fuel-rich condition.

Selection of Ionic Liquids and Characterization of Hypergolicy With Hydrogen Peroxide

“…Handling of pure hydrides is challenging, because of their high reactive sensitivity to air and moisture (Sippel, et al 2011). Groups in Korea (Kang, Lee and Kwon 2017), Poland (Florczuk and Rarata 2017) In literature, it has been reported that some ILs are hypergolic with different oxidizers like white fuming nitic acid (WFNA), red fuming nitric acid (RFNA), NTO and HP (Sebastiano, et al 2014) (Zhang and Shreeve 2014). Very low ignition delay times for WFNA have been reported in the order of 1 ms (Zhang, et al 2016).…”

Atomic Perspective about the Reaction Mechanism and H2 Production during the Combustion of Al Nanoparticles/H2O2 Bipropellants

“…For example, Kang et al reported that a new bipropellant coupled with 98% H 2 O 2 delivers higher thrust than a combination of hydrazine and N 2 O 4 . 18 The contacts of H 2 O 2 with various fuels, such as alcohols, ketones, hydrocarbons, kerosene, and ionic liquids, are beneficial to develop hypergolic propellant formulations. 12,19−22 With respect to fuels, Al is the most popular due to its favorable properties, such as high energy density (30.5 kJ/g), wide availability, low cost, and environmentally benign products.…”

“…These catalysts include metallic Ag, Pt/Al 2 O 3 , Ir/Al 2 O 3 , MnO x /TiO 2 , and MnO x /ZrO 2 . − The reaction of H 2 O 2 with a fuel can also generate a high specific impulse, functioning as a bipropellant. For example, Kang et al reported that a new bipropellant coupled with 98% H 2 O 2 delivers higher thrust than a combination of hydrazine and N 2 O 4 . The contacts of H 2 O 2 with various fuels, such as alcohols, ketones, hydrocarbons, kerosene, and ionic liquids, are beneficial to develop hypergolic propellant formulations. ,− …”

Evaluation of the possibilities of adapting a constant volume combustion chamber for research on ignition of hypergolic propellants under low and high-pressure conditions

“…The schematic of the drop test stand is presented in Fig. 1 [9]. The procedure for this experiment is simple: a droplet of an oxidizer is released from a syringe or pipette; it falls down into the pool of a propellant stored in a vessel, e.g.…”

“…1. Schematic drawing of the drop test stand [9] The drop test allows the exploration of the variations of ignition delay under two extreme operating conditions: extreme fuel-rich combustion (oxidizer released as a droplet, fuel in the pool); or extreme oxidizer-rich combustion (fuel released as a droplet, oxidizer in the pool). The whole process is recorded by a high-speed camera.…”