Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
David Alexander IV - Tuskegee University
Co-Author(s): John Solomon and Kyran Caines, Tuskegee University, Tuskegee, AL
Flow instabilities are inherent in high speed flow applications and play a crucial role for generating hostile dynamic interactions in fluids. With flow control schemes, these inherent instabilities can be tailored to achieve favorable outcomes. The resonance enhanced micro-actuator nozzle (REM-nozzle) used in this research is a device developed for high speed flow control. This type of fluidic actuator, having neither heavy nor complicated hardware/electronics, was observed to provide high momentum perturbations over a wide range of frequencies (1- 60 kHz). The REM has been designed and tested by several researchers for various flow control applications. In this research, we use REM technology to design fuel nozzles applicable for high speed combustors. Design and development of REM nozzles, using patented REM technology developed by Solomon et. al [2,3], and a study on tailored nozzle jet flow will be presented in the Emerging Researchers Conference. REM nozzles are expected to enhance the mixing of flow from a nozzle. We have designed REM actuators in the ultrasonic frequency range, 20-40 kHz. At this frequency range, the natural instabilities of the nozzle jet are expected to be amplified leading to more entrainment of the surrounding fluid. The high frequency disturbances imposed to the micro-jet flow near its nozzle exit will excite the shear layer instabilities to create more vortices in the nozzle flow to enhance mixing. Such nozzles can potentially be used to enhance mixing inside a high speed combustor. This design is composed of 4 major elements. An under expanded source jet from a 1mm nozzle, a constricted cavity, 4 micro-nozzles through which the pulsed high frequency micro-jets flow out, surrounding a 1mm nozzle through which the nozzle jet is flown out. A semi-empirical correlation derived by Solomon  is used for designing REM nozzles. The design volume of the actuator cavity is 8mm3. The design details of REM nozzles will be presented in the conference. This includes microphone data of REM frequency, laser based imaging of tailored nozzle flow using the micro-Schlieren technique. We are currently studying two REM nozzle designs which will be fabricated and tested before the conference presentation. Experiments will initially be conducted at the Florida Center of Advanced Aero-Propulsion. In addition, we will develop a flow diagnostic laboratory at Tuskegee University during the project.
Funder Acknowledgement(s): Funding was provided by NSF/ HBCU-UP grant to John Solomon.
Faculty Advisor: John Solomon, JSolomon@mytu.tuskegee.edu