Particle Characterization for the Aerospace Industry

The aerospace industry has many diverse applications for particle size analysis and rheology. These vary from safety testing to engine design and propulsion testing.

Aircraft Icing studies

Recently there has been a great deal of research in the study of aircraft icing. The behavior of ice on the aircraft wing in freezing conditions has to be studied as part of aircraft development. The performance of wing de-icers can be studied by a Malvern Spraytec droplet sizing system. Any ridges of ice formed upon the wing should not cause any movement of the components present; the movement of an aileron in flight could have catastrophic consequences. The Spraytec can be fitted either side of a wind tunnel into which a wing cross-section can be placed or in a hanger downstream of an aircraft.

The large working range of the Spraytec makes it ideal for this application. Use of the system enables the effect that changes in humidity and temperature have on the sizes of the ice crystals to be rapidly seen. The instrument also has an air purge system, which prevents any fogging of the optics.

Malvern rheometers are used routinely to simulate how the de-icing fluid will flow during takeoff and landing when subjected to varying conditions of shear and temperature. Many of our rheometers can directly simulate the potential shear conditions that have caused de-icing agents to fail, and enable formulation of materials that can withstand these rigorous conditions.

Jet Engines

The droplet size in a fuel spray influences the speed and efficiency of combustion, which impacts directly on engine performance.
The Malvern Spraytec system has found use in studies looking at fuel injector systems for jet engines. Fuel sprays are extremely highly concentrated and rapid. Traditional laser diffraction methods are too slow and will get incorrect distribution data reported due to the highly concentrated spray causing multiple scattering (which gives a smaller particle size than expected). The Spraytec can measure at speeds up to 2500Hz and has a multiple scattering correction, which enables accurate measurement.

In addition, when fuels are sprayed they are subjected to very high shear rate conditions and proper dispersion of the spray is essential to optimum performance. Malvern rheometers enable simulation of these high shear rate conditions to determine how well the fuel spray will perform.

Metal powders

The particle size distribution of metal powders (used for rocket propulsion) or alloys (such as titanium used for aircraft body parts, or bronze used for sintered metal filters in oil filter extraction) can easily be measured by the Malvern Mastersizer 2000. Metal powder atomization production processes can be followed using the Malvern Insitec system. Nano-sized metal powders (such as the aluminium powder used to propel the Space Shuttle) can be sized using the Malvern Zetasizer Nano S.

Malvern rheometers can characterize the rheological properties to also aid in measuring how well dispersed the particles are and to assist in achieving the proper green strength of a molded part.