| Popis: |
In many aerodynamic studies where the flow patterns need to be identified, flow visualization is a tool that is commonly used. Some of the classic forms of flow visualization are the use of smoke, tuffs, oils, and in water, dye injection, hydrogen bubbles, and light sheets. Typically the main purpose of flow visualization is to gather qualitative information not quantitative data. Because of developments in PC based image acquisition and analysis, quantitative data has potentially become simplified and inexpensive to obtain. In this project a method was developed to gather quantitative data from flow visualization using off-the-self consumer based imaging hardware and an author developed image processing code. This method was developed to measure the velocity profile, and estimate the circulation of a vortex wake in a water tunnel, using a hydrogen bubble sheet with cross sections illuminated by a laser light sheet. Introduction Flow visualization methods such as smoke, tuffs, oils and in water, dye injection, hydrogen bubbles, and light sheets are great tools to better understand the flow characteristics around a body. All of these methods produce important qualitative information and “pretty pictures” but they do not typically result in any quantitative data (e.g., velocities, lift,. . .). There are however, enhanced flow visualization methods that are quantitative such as Particle Imaging Velocimetry (PIV). With this method it is possible to visualize the flow behavior and to obtain accurate velocity measurements. PIV is a very powerful method, but it requires very expensive cameras, high dollar scanning or photo capture boards, and considerable amounts of data reduction before any quantitative data can be obtained. 1. Graduate Student, Student Member of AIAA 2. Graduate Student, Student Member of AIAA Copyright |
