Project:	Measuring the turbulent free-surface wake of a bluff body using defocusing digital particle image velocimetry (DDPIV)
Disciplines:	Mechanical Engineering, Physics, Computer Science, Mathematics
Mentor:	Cong Wang, Assistant Professor, (EAS), cong-wang-1@uiowa.edu, Phone: 626-437-8816
Background:	NOTE 1: This project is being offered by a Caltech alum and is open only to Caltech students. The project will be conducted at the University of Iowa in Iowa City, Iowa. NOTE 2: Dr. Wang is offering three different projects. Please include "Caltech SURF + project title" in the subject line when emailing Dr. Wang. The turbulent free-surface wake behind a surface vessel (e.g., an aircraft carrier) critically affects its safety and daily operation. However, the free-surface wake flow involves complex mass and momentum transport processes in the three-dimensional space, which is challenging to understand and model. In this regard, accurately capturing the physics of 3D turbulent free surface wake flow would enable the development of reliable wake flow models, which is fundamentally relevant to many naval applications. Recently, supported by the Office of Naval Research (ONR), a collaborative research project (2022 - 2026) involving researchers from Caltech (experiment, led by Prof. Mory Gharib), University of Iowa (experiment, led by Prof. Cong Wang), and Stanford (simulation, led by Prof. Ali Mani) was initiated. In this project, the state-of-art 3D flow diagnosis technique (DDPIV) will be integrated with the numerical simulation technique (macroscopic forcing method) to investigate the physics of turbulent free-surface wake flow.
Description:	The student will learn and adapt the DDPIV system in measuring the 3D turbulent wake flow behind a bluff body. The DDPIV measurement will be combined with the more conventional 2D-PIV measurement, for the purpose of results validation and fine-tuning the system parameters. The student will have extensive exposure to optical measurement, high-speed camera, and advanced 3D flow diagnosis techniques.
References:	Pereira, F., Gharib, M., (2002) “Defocusing Digital Particle Image Velocimetry and the Three-Dimensional Characterization of Two-Phase Flows”, Measurement Science and Technology, vol. 13, pp. 683-694 Pereira, F., Gharib, M., Dabiri, D. and Modarress, M.,, (2000) “Defocusing DPIV: A 3-component 3-D DPIV Measurement Technique. Application to Bubbly Flows” Experiments in Fluids, vol. 29, pp. S78- S84 Pereira, F., Heinrich, S., Graff, E.C., Gharib, M., (2006) “Two-frame 3D particle tracking,” Measurement Science and Technology, vol. 17, No. 7: 1680–1692
Student Requirements:	Basic knowledge and interest in optics and mechanics is needed. Skills in hands-on experiment (optics, camera, laser, etc) and data analysis (matlab, python, etc) are preferred.
Programs:	This AO can be done under the following programs:   Program    Available To        SURF    Caltech students only  Click on a program name for program info and application requirements.