title: Simultaneous velocity and pressure measurements using luminescent microspheres.
abstract: Using the technique of modified rapid lifetime determination, pressure-sensitive microspheres, known as PrSBeads, were used to make quantitative oxygen measurements over two-dimensional areas within gaseous flows. Aerosolized PrSBeads in carrier gases of varying oxygen concentrations demonstrated point measurement precisions on the order of 0.1%-1%. A charge-coupled device featuring a double image frame (DIF) feature was used to make spatially resolved pressure measurements within gas phase flows. Errors on the order of 0.5 atm for one standard deviation were demonstrated when 2 x 2 pixel binning (162 x 128 pixel overall resolution) was used, but improved to 0.003-0.005 atm with the use of 32 x 32 pixel binning (10 x 8 pixel overall resolution). Experiments demonstrate the ability to resolve the oxygen concentration differences between a N(2) jet and the surrounding ambient air environment and the ability to measure instantaneous air pressure changes within a square syringe as the plunger is moved in and out. In addition, instantaneous velocity measurements of the airborne PrSBeads in a square syringe were achieved using digital particle image velocimetry at frame rates of 6.4 Hz, thus validating PrSBeads as a tool to simultaneously measure the velocity and pressure within an aerodynamic flow.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Fletcher
authors.initials: F
authors.lastname: Kimura
authors.forename: Jesse
authors.initials: J
authors.lastname: McCann
authors.forename: Gamal E
authors.initials: GE
authors.lastname: Khalil
authors.forename: Dana
authors.initials: D
authors.lastname: Dabiri
authors.forename: Younan
authors.initials: Y
authors.lastname: Xia
authors.forename: James B
authors.initials: JB
authors.lastname: Callis
mesh_terms: D000336:Aerosols / Q000737:chemistry; D000388:Air; D000399:Air Pressure; D000465:Algorithms; D004867:Equipment Design; D005740:Gases / Q000737:chemistry; D049449:Luminescence; D008163:Luminescent Measurements / Q000295:instrumentation* / Q000379:methods*; D008863:Microspheres; D008956:Models, Chemical; D009038:Motion; D009584:Nitrogen; D010100:Oxygen / Q000737:chemistry; D011312:Pressure; D013696:Temperature; D013997:Time Factors
chemical_list: D000336:Aerosols; D005740:Gases; D009584:Nitrogen; D010100:Oxygen