Engineers, food scientists collaborating to cook new gelled rocket fuels

Washington, January 22 (ANI): Engineers are joining forces with experts from other branches of science to develop a new type of gelled fuel, in the hope that it would improve the safety, performance and range of rockets for space and military applications.

"This is a very multidisciplinary project," said Stephen Heister, the Purdue University professor of aeronautics and astronautics who is leading one of two teams on the project, which is funded by the U.S. Army Research Office.

He believes gels to be safer than liquids because they make for lesser leakages.

The researcher says that gels can even be helpful for the military, as it can help better control rockets than is possible with solid fuels now used.

Heister also says that motors running on gelled fuels could be throttled up and down and controlled more precisely than conventional rockets that use solid propellants.

"You can turn the engine on and off, you can coast, go fast or slow. You have much greater control, which means more range for missiles. The gelled propellants also tend to have a little more energy than the solid propellants," he said.

He further says that gelled fuels may also find application in thrusters to position satellites and on NASA space missions.

Paul Sojka, a professor of mechanical engineering and an associate director of the project, is building an experiment to take high-speed videos of the gelatinous fuel's behavior. Jets of the gel form during the fuel-injection process.

"These jets are wiggling, there are pulsations, and those pulsations, we believe, lead to the formation of specific spray patterns and droplet formation. The fluid mechanics of gels are quite challenging. The viscous properties of the gel change depending on how fast it's flowing, which is not true of common liquids such as water or gasoline," Sojka said.

Carlos Corvalan, an associate professor of food science, has revealed that the project will tap the expertise of food scientists and food engineers.

"Gels are more complex than ordinary solids and fluids. Fluids are characterized by viscosity, and solids are characterized by elasticity. Because gels share properties of both solids and fluids, they possess viscoelastic properties, or a combination of both," Corvalan said.

The objective of the research is to be able to consistently create the relatively small, uniform droplets that would be needed for rocket propulsion, and food scientists are familiar with processes used to create droplets in foods.

"The texture of those foods is closely associated with the average size and range of sizes of droplets. In a combustion chamber you also want to control droplet size, but for a different reason - to precisely control combustion. You want uniform combustion, and for that you need controlled drop size," said Osvaldo Campanella, a professor of agricultural and biological engineering.

The researchers will initially work with water-based gels that simulate fuels, and later conduct experiments using actual propellants.

Information from experiments and modelling will be used to design systems that have improved combustion. (ANI)