Steven L. Ceccio

Steven L. Ceccio received his BS degree in mechanical engineering from the University of Michigan in 1985. He received his MS degree in 1986, and his Ph.D. in 1990 both in mechanical engineering from the California Institute of Technology. He currently has appointments in Naval Architecture and Marine Engineering, Mechanical Engineering, and Applied Mechanics at the University of Michigan.

Prof. Ceccio has focused on the study of multiphase flows through the creation of a world-class laboratory at the University of Michigan and through the use of large-scale testing facilities located throughout the country. He has concentrated on the experimental examination of these complex flows with the goal of understanding fundamental processes responsible for their underlying dynamics and transport. A brief summary of his more recent research activity is presented here. Prof. Ceccio is a world expert in the area of cavitating flows. He continues to examine a variety of cavitating flows of naval interest with the support of the Office of Naval Research (ONR), including bubble-boundary layer interactions, partial sheet cavitation, the transition of partial sheet cavitation to unsteady cloud cavitation, and the scaling of cavitation inception. His research effort has recently focused on the issue of, “limited event-rate” cavitation. These discreet cavitation events can occur in the tip vicinity of propulsors and are often detected through sound emission. As part of this effort, he has constructed a new re-circulating water tunnel to conduct cavitation research at UM. His efforts are now concentrated on understanding vortex-vortex interactions that lead to cavitation inception, and the active suppression of vortex inception using the injection of water and polymer solution in the region of vortex roll-up.

A major project, designated “HIPLATE,” has been undertaken to explore the physical processes responsible for friction drag reduction through the examination of well-controlled wall bounded turbulent shear flows, under the sponsorship of the Defense Advanced Research Project Agency (DARPA) and ONR since 2000. An experimental program is also being conducted in the Large Cavitation Channel to examine both micro-bubble and polymer friction drag reduction. Prof. Dave Dowling and Prof. Marc Perlin of Naval Architecture and Marine Engineering are co-investigators on this project. Prof Ceccio and his team designed and built a test model to produce a wall-bounded shear flows capable of achieving Reynolds numbers up to 200 million. A series of experiments were conducted in Memphis between 2000 and 2006 to study the underlying physics of micro-bubble and polymer drag reduction, and these data underlay the development and validation of numerical models by three other teams sponsored by DARPA (Stanford, General Dynamics, and Penn State ARL). The results from theses high Reynolds number experiments have proved to be critical to the evaluation of micro-bubble and polymer drag reduction.

During this project, the UM team developed a new drag reduction technology employing increased gas fluxes near the ship hull, Air Layer Drag Reduction (ALDR). We are currently working of a LCC test to examine ALDR and large-scale cavity flows for drag reduction on surface ships. This is an experimental and numerical effort that resulted in a large-scale LCC experiment in Winter 2007. Our goal is to examine the stability and closure of large, ventilated partial cavities, along with ALDR. We are also examining the use of indentations or pockets within a hull to form partial cavities for Partial Cavity Drag Reduction (PCDR). Our next experiment is scheduled for the Spring of 2009, when we will examine how small and large-scale flow perturbations may influence the formation and stability of air layers and partial cavities. As part of the project, we are designing a gate apparatus to permit the free-surface operation of the LCC. ONR has formed a team of computational researchers from the Navy labs, Stanford, Iowa, and, Dynaflow Inc. to conduct a coordinated effort to simulate both the ALDR and PCDR flows. We are currently working with various vendors and ONR to evaluate the use of super-hydrophobic coatings for friction drag reduction. We are measuring the friction coefficient developed on these surfaces by a high Reynolds number turbulent boundary layer. In a future study, micro-flow visualization will be used to examine the near surface flow and the possible presence of surface gas pockets. We also intend to examine how these coatings might enhance the formation of near surface air layers. Prof. Ceccio has worked with Dr. O’Hern to develop Gamma Densitometry Tomography and Electrical Impedance Tomography (EIT) systems for the measurement of opaque multiphase flows. EIT systems employ electrical measurements at the boundary of a domain to infer the distribution of electrical conductivity within the domain. Since the conductivity of the phases within a multiphase flow can significantly differ, knowledge of the electrical impedance distribution can be used to determine the distribution of material phases. These systems have been used to examine liquid-gas, gas-solid, and three-phase flows in bubble column reactors and gas-solid riser reactors. This project was part of an industry-government-university consortium called the Multiphase Fluid Dynamics Research Consortium. Our work on gas-solid multiphase flows continues with an effort to examine liquid dispersion and evaporation in gas-solid risers, and we have joined with Prof. Volker Sick to develop Pulsed Laser Induced Fluorescence (PLIF) based probes for gas-solid flows.

We are continuing our program to develop radiation based flow diagnostics through the design and construction of a cinemagraphic x-ray system to be implemented for gas-solid and high-void fraction bubbly flows under the support of ONR. We will use this system to examine the formation and break-up or air layers and the dynamics of sheet-cloud transition of partial cavities. We have received support from the Department of Energy study the dynamics of gas-solid flows, and to develop measurement techniques for the measurement of gas and solid phase distributions. We have used LDV measurements to characterize a penetrating jet flow into a two-dimensional gas-solid fluidized bed, and a companion numerical simulation effort will be conducted with Prof. Jennifer Sinclair-Curtis of the University of Florida. We will next use use x-ray densitometry to characterize the solid phase distributions within the bed.

Prof. Ceccio has also developed novel optical diagnostics, including a high repetition rate Particle Imaging Velocimetry system. CPIV has been used to examine turbulent combustion through collaboration with Prof. James Driscoll of AERO. We are currently working on a two-camera system that will acquire the images digitally and combine CPIV with cinemagraphic laser induced fluorescence. This effort is sponsored by NSF and ONR. Also, we have received support form the Air Force Office of Scientific Research (AFOSR) to purchase a high repetition rate laser to perform pulsed laser induced fluorescence measurements in tandem with our flow field measurements. We are currently using the CPIV system to examine the resonant flow over cavities at low Mach number but high Reynolds Number. Our goal is to combine CPIV and PLIF to study the dynamics of combusting flows.