简介:The aim of this work was to understand the physical requirements as well as to develop
methodology required to employ Time Resolved Digital Particle Image Velocimetry
(TRDPIV) for measuring high speed, high magnificati简介:The aim of this work was to understand the physical requirements as well as to develop
methodology required to employ Time Resolved Digital Particle Image Velocimetry
(TRDPIV) for measuring high speed, high magnification, near wall flow fields. Previous
attempts to perform measurements such as this have been unsuccessful because of
both limitations in equipment as well as proper methodology for processing of the data.
This work addresses those issues and successfully demonstrates a test inside of a
transonic turbine cascade as well as a high speed high magnification wall jet.
From previous studies it was established that flow tracer delivery is not a trivial task in a
high speed high back pressure environment. Any TRDPIV measurement requires
uniform spatial seeding density, but time-resolved measurements require uniform
temporal seeding density as well. To this end, a high pressure particle generator was
developed. This advancement enhanced current capability beyond what was previously
attainable. Unfortunately, this was not sufficient to resolve the issue of seeding all
together, and an advanced data reconstruction methodology was developed to
reconstruct areas of the flow field that where lost do to inhomogeneous seeding. This
reconstruction methodology, based on Proper Orthogonal Decomposition (POD), has
been shown to produce errors in corrected velocities below tradition spatial techniques
alone. The combination of both particle generator and reconstruction methodology was
instrumental for successfully acquiring TRDPIV measurements in a high speed high
pressure environment such as a transonic wind tunnel facility.
This work also investigates the development of a turbulent wall jet. 详细>