Probe into Ventilated Cavitation Physics with Novel Imaging Techniques
Abstract
The proposed measurements will be used to provide deliverables for ventilated supercavitation as follows: (1) the characteristics of supercavity internal flows under various critical flow conditions; (2) the physical mechanisms coupling the internal flows and external conditions; (3) physics-based models predicting ventilation demand and dynamic behaviors of supercavitation over a wide range of operational conditions. Multiphase flows, e.g. flows of gas-liquid or different immiscible liquids, occur in a broad range of science disciplines and industrial operations. Ventilated cavitation, referring to a process of injecting gas into liquid, is an active means of using multiphase flows for a broad range of applications including flow control, drag reduction, antifouling, noise suppression, waste water treatment and enhancing turbomachinery durability, etc. Despite various promising concepts of using ventilated cavitation, its realization and further development are strongly limited by the lack of detailed understanding on physical processes involved in it. Particularly, in ventilated supercavitation, there is little consensus on observations and the empirical formulations derived from different prior studies even under simple flow conditions. These discrepancies have been generally attributed to the difference in experimental conditions, but the exact bearing of the influence of these conditions on the supercavitation process is not well understood at a fundamental physical level. As pointed out by a number of prior studies, the lack of physical understanding is inherently caused by the availability of our experimental methods to probe into the detailed processes characterizing gas-liquid interaction. As far as ventilated cavitation is concern, this entails high-resolution quantification of the flow field within the ventilated cavity and at gas-liquid interface as well as the bubble dynamics across the interface, imposing significant challenges to the existing flow diagnostic techniques. Therefore, the overall scope of the proposed research includes: (1) developing novel experiment methodology that enables characterization of key physical processes involved in gas-liquid interaction; (2) conducting systematic investigation of the physical mechanisms for a specific case of ventilates cavitation using the developed methodology; (3) establishing a physics-based framework for general applications using ventilated cavitation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141612755
Entities
People
- Jiarong Hong
Organizations
- Office of Naval Research
- Regents of the University of Minnesota
- United States Navy