High Velocity Drop Impact Experiment
Overview
Schematic of the high velocity droplet impact (HVDI) apparatus (Click for details).
This experiment is an investigation into the atomization and vaporization mechanisms that occur prior to ignition in hypergolic propellants. The goals of the experiment are to understand the physical processes that control pre-ignition gas production, to understand how those processes affect ignition delay and identify which conditions will prevent ignition. This research is directly applicable to modeling hypergolic ignition, preventing “hard-starts” in hypergolic thrusters, as well as identifying and advancing alternative hypergolic propellants. Funding for this experiment is provided by an Army Research Office (ARO) MURI grant.
Drop test experiment performed with rocket grade hydrogen peroxide and a sodium borohydride based fuel.
Capabilities
A 2.3 mm diameter drop of MMH impacts a pool of RFNA at 1.2 m/s which results in vaporization of the propellants but not ignition. 2 ms elapsed between frames.
- Chamber Conditions:
- Variable chamber pressure from 0.05 - 10 atm, chamber temperature from 0° to 50°C, control over ambient gas (air, oxidizer, inert, etc.).
- Droplet impact velocities from 0.1 - 3 m/s.
- Diagnostics:
- High speed imaging of droplet contact, reaction and ignition process.
- IR imaging with thin filament pyrometry and UV intensified chemiluminescence (OH, NH, etc.) imaging.
- Chamber pressure rise and temperature measurements.
Accomplishments
- Experimental droplet contact data to support current modeling efforts.
Multimedia
| Description: A droplet of MMH lowered into a pool of RFNA at 0.1 m/s resulting in vapor
production, a pressure pulse dispersing propellants, and eventually ignition in the dispersed vapors.
Year: 2010 Sponsor: MURI | |
| Description: Experiment showing the contact between a 2.3 mm droplet of MMH and a 50 μL pool of
10° C WFNA at 1.3 m/s. The lack of explosion of gases is a point of current investigation.
Year: 2012 Sponsor: MURI | |
| Description: Experiment showing the contact between a 2.3 mm droplet of MMH and a 50 μL pool of
20° C WFNA at 1.3 m/s. The resulting explosion of gases is a point of current investigation.
Year: 2012 Sponsor: MURI | |
| Description: Experiment performed to visualize the contact and early stage interaction between a falling MMH droplet and RFNA pool at very high frame rate (75,000+ fps) in support of current modeling effort.
Year: 2012 Sponsor: MURI | |
| Description: Image-based video analysis of contact and resulting explosion between a MMH droplet and a RFNA pool. Light absorption of the test area and gas evolution velocity are tracked frame by frame during the experiment.
Year: 2013 Sponsor: MURI |
People
Faculty
Dr. Timothée Pourpoint, Purdue University
Dr. Stephen Heister, Purdue University
Researchers
Jordan Forness, M.S. (Graduated)
Erik Dambach, Ph.D. (Graduated)