SBIR-STTR Award

This project will develop fuel injection technology that is inherently insensitive to variation in liquid physical properties. Generally physical properties can impact the injector discharge coefficient which in turn impacts liquid velocity and mass flow for a given injector pressure drop. ?Under certain circumstances, the discharge coefficient can be made to be insensitive to these properties. ?Hence the approach taken is to modify the injector configuration to consistently behave as it would under these certain circumstances. Extensive experimental and simulation work will be used to create configurations with a wide range operation under these conditions.

Benefit:
The benefits of this development will be injectors for fuel or other fluids which have no dependency on liquid physical properties. This will result in reduced variation in injection velocity and associated penetration. The conditions that will be targeted are also expected to provide improved atomization behavior which has potential benefit for many combustion systems.

This project is developing strategies for liquid fuel injection that reduce the sensitivity of the injection process to liquid physical properties. The injection process depends on liquid properties such as viscosity or surface tension. Changes in properties can alter the distribution of the fuel ahead of the combustion process. Changing fuel temperature can change fuel properties. Alternative fuels may have different physical properties than the baseline fuel. By mitigating the dependency of the injection process on fuel properties, better control and understanding of subsequent combustion process can be attained. The goal of this project is to employ cavitation to both reduce sensitivity to changes in fuel properties and enhance atomization. Cavitation isolates the bulk of the fuel from wall contact, reducing the impact of viscosity and accelerates atomization, reducing the dependence on surface tension. To maximize benefit of cavitation, injector inlet shapes and cross sections will be optimized to minimize sensitivity of the injection process to liquid properties. The project involves a combination of high fidelity simulations coupled with detailed experiments in which specific injector geometries will be identified that will greatly reduce sensitivity to fuel properties. Both reacting and non-reacting studies will be carried out