Hypergolic propellants are used in rocket propulsion to power the rocket engine using spontaneous combustion. This project involved the development of a spray ignition setup for the combustion of hypergolic propellants. A theoretical injector system was designed and validated. Experiments were performed using High Speed Imaging to study impingement characteristics of a triplet injector. This work was conducted under the guidance of Prof. Arindrajit Chowdhury at the Internal Combustion Engines Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Bombay.

Some results are listed below -

  • A combustion chamber withstanding a pressure of 30 bar was modelled on SolidWorks and structural analysis was conducted on ANSYS.
  • A theoretical injector system was modelled and validated.
  • Three types of propellants were tested experimentally with High Speed Imaging to study the impingement characteristics of the triplet injector.

Note: The propellants shown in the image are Water-Water for pressures 1, 6 and 10 bar from left to right.

Impingement Characteristics of the Triplet Injector

Top to bottom: High Speed impingement characteristics for 3 types of propellant combinations at pressures 1 bar and 11 bar

Water-HEHN-Water for pressure = 1 bar

Water-HEHN-Water for pressure = 11 bar

Water-UH50-Water for pressure = 1 bar

Water-UH50-Water for pressure = 11 bar

Water-Water-Water for pressure = 1 bar

Water-Water-Water for pressure = 11 bar

Modelling of the Combustion Chamber

The chamber was modelled on SolidWorks to withstand a pressure of 30 bar and was structurally analysed using ANSYS.

For a pressure of 60 bar and factor of safety = 0.456, the glass was seen to incur failure at the viewing port. Toughened borosilicate was chosen as the glass material.

Total deformation was studied and the right viewing port was seen to incur maximum deformation.

The experimental setup (left) was used to study impingement characteristics of three types of propellant combinations.

Impingement Results

The plot (left) depicts the change in average cone angle with increasing pressure. The propellant used here is Water-UH50-Water. On average, the cone angle is seen to increase with increasing pressure.

To view the flow at the point of increase (6 bar), click here.

FLOW RATE VISUALIZATION

Click on the links to visualize the flow rates at 3 pressures -