099-Hypergolic ignition of liquid storable propellants

099-Hypergolic ignition of liquid storable propellants

  • Contract :Ph.D.
  • Duration :36 months
  • Working time :Full-time
  • Experience :Entry Level
  • Education level :Master’s Degree, MA/MS/MSc

Your mission at CNES :

European regulation “REACH” is likely to ban the use of current storable propellants such as hydrazine, due to their high toxicity. Thus, new storable liquid propellants have to be identified and selected to be respectful of both human health and the environment, keeping at least similar performances. CNES, ISAE-ENSMA and PPRIME Institute have joined efforts to investigate ignition and combustion of possible alternative propellants. “PERGOLA”, a unique experimental facility in Europe dedicated to such propellants, was validated in 2015 for the characterization of storable propellants performance (combustion pressure, thrust) in the conditions of targeted space applications. ACSEL, a smaller experimental facility, allows multiple parametric studies thanks to its versatility.
Among the oxidizers of interest, hydrogen peroxide is a promising candidate. However, very few fuels are enough reactive with hydrogen peroxide with regard to ignition time as low as 100 ms or less, so that a safe use in a hypergolic bipropellant thruster can be allowed [1]. Kerosene and ethanol are not included. Thus, in order to get a hypergolic reaction between a hydrocarbon and hydrogen peroxide, additives must be added to the fuel to help start the reaction. Two types of additives are commonly used in the literature [2], [3]:
So-called ""catalytic"" additives, which accelerate the exothermic decomposition reaction of hydrogen peroxide into oxygen and water vapour, thus creating thermodynamic conditions favorable to the autoignition of the fuel.

Additives referred to as ""reagents"" or ""promoters"", which react violently (ignition, explosions) in contact with hydrogen peroxide, therefore acting as an ignition system for the fuel.
The most active catalytic additives known are salts and metal oxides [1], [2], [4]–[6]. Many studies use magnesium acetate tetrahydrate (MAT) [6]–[9]. They are, in general, easy to use and do not show significant toxicity (combination of volatility, grain size, inhalation toxicity).
Reactive additives, on the other hand, provide shorter ignition times [2], [4], [10] and greater heat release (about 7 times more than with catalytic additives). These are usually metal hydrides or pyrophoric compounds [11]–[13].

Recently, studies have tested the use of hypergolic ionic liquids to make a fuel/hydrogen peroxide couple hypergolic [10].
The objective of the Ph. D work is to study and implement the hypergolic ignition of liquid bipropellants using hydrogen peroxide as an oxidizer. Such properties are attractive as they will allow removing the ignitor in future engine. After a literature review on hypergolicity, alternative route will be explored, possible candidates among fuel and additives will be downselected, procured and/or synthesized so that first drop tests can be carried out at IC2MP. The most promising solutions will be further evaluated on the combustion benches of the PPRIME Institute. The use of these propellants will require combustion control under specific conditions, especially for the injection process and during the transient ignition phase. The in-situ characterization of the local properties of turbulent reactive flow will be carried out using high-speed visualization (broadband chemiluminescence, radical-filtered emission), laser diagnostics (reactive granulometry, velocity, fluorescence, spectrometry) as well as rapid physical measurements (pressure, thermal losses).

For more information, contact from PPRIME/IC2MP

Candidate profile searched:

Experience: Master in Chemistry, Combustion, Fluid mechanics, Energetics

We suggest you to contact first the PhD supervisor about the topics and the co-financial partner (found by the lab !). Then, prepare a resumé, a recent transcript and a reference letter from you M2 supervisor/ engineering school director and you will be ready to apply online !

CNES will inform about the status of your application in mid-June.

More details on CNES website :

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