Student(s): Hana Hussain, Nargis Mubarak
Project: Mechanical Metamaterials for Flow Control
Advisor(s): Natasha Vermaak
Abstract
Fundamental fluid mechanics states flow can be categorized as being in a laminar state or turbulent state. The transition between these states is dictated by the perturbation of instability modes. Current efforts to control this transition involve adjusting the flow itself, but few engineers have looked at adjusting the duct material itself to control flow behavior. Instability modes in a flow over a material propagate phonons, which are quanta of vibrational energy. A metamaterial is an engineered material whose properties arise from the structure of the material. This lab is investigating the validity of phononic metamaterials and their ability to manipulate turbulent flow.
Preliminary validation was explored through online simulations. This model was built in ABAQUS, a finite element analysis software. The model underwent around 40 iterations by adjusting the cyclic loading, material properties, and cross sectional geometry. Ultimately we were able to model the frequency–displacement relationships that mirrored theoretical phononic band gap predictions (50 Hz range). The theory could now be tested with real world experimentation. The team built a prototype of the phononic metamaterial using alternating layers of silicone and aluminum using various 3D printed molds and the metal shop. To test the prototype, we designed and manufactured a custom vibrational hammer apparatus, as our in-house machine only went up to 10 Hz. We built a horizontal swing to minimize compressive and normal forces and then designed a cam-follower-motor system to deliver the 300 Hz frequency necessary to see a band gap.
About Hana Hussain
Major: Mechanical Engineering and Mechanics
Hana Hussain is a 4th year mechanical engineering student from Connecticut. In 2024, she was awarded a Clare Boothe Luce Fellowship for women engineers and joined Dr. Natasha Vermaak’s Thermostructural Lab. Hana is also pursuing an aerospace engineering minor and served as president of LU Aero, an aviation engineering club, which gave her the opportunity to participate in the AIAA Design Build Fly Competition. Hana is particularly interested in research that investigates the intersection between structural materials and aerospace applications. Within the P.C. Rossin College of Engineering, Hana has also held positions as student lab supervisor in the Dravo Metal Shop, peer mentor for the senior mechanical engineering lab class, and student mentor at Lehigh’s Summer Engineering Institute. Outside of engineering, Hana is an avid member of the Muslim Student Association and Debate Team.
About Nargis Mubarak
Major: Mechanical Engineering and Mechanics
Nargis Mubarak is a sophomore mechanical engineering student at Lehigh University. She recently joined Dr. Vermaak’s thermostructural lab with a focus on the last phase of the research: building the vibrometer to validate metamaterial dampening of flow instability, with the goal of flow control in phononic metamaterials through applications in material design and controlled systems. Outside of the lab, Nargis is a member of the LU Rocket Association, working on the liquids team to build an injector design for a hybrid propulsion system utilizing nitrous oxide with sulfur dioxide additive. As an aerospace engineering minor candidate, she aims to deepen her understanding and integrate thermodynamics and aerospace principles for future research and applications. In addition, she volunteers with the CSO and is an avid member of the academic fraternity PSP. Nargis is from Falls Church, Virginia and enjoys spending quality time with family, geography puzzles, and watching the real football.