An Experimental Research Project on Sinusoidal Pulsatile Pipe Flows Part 1: Presentation of Software Programming Utilized for Measurements and Data Acquisition

Abstract:- An experimental study conducted on pulsatile pressure and velocity measurements inside a sinusoidal air flow medium is presented. Controlled oscillation frequency, f and velocity amplitude ratio, A1 are satisfied via so called mass flow control (MFC) unit. Velocity and pressure data through the signals of hotwire anemometer and pressure transmitters are acquired and processed via the data acquisition system which is composed of hotwire anemometer and probe, pressure transmitters, in connection with an IOtech Daq3001 USB board installed. The operation of the measurement chain, signal-data acquisition and data processing is handled through the devised software program named as Time Dependent Flow Control.vi (TDFC.vi) in LabView 2009SP1 ® environment. In this paper, the details of the software programming utilized for the oscillation generation, control and relevant data acquisition in the experimental ranges of time-averaged Reynolds number, taRe of 1019±35 ≤ taRe ≤4817±164, oscillating Reynolds number, osRe of 107±4 ≤ osRe ≤4261±145, velocity amplitude ratio, 1A of 0.05±0.0017 ≤ 1A ≤ 0.96±0.03 and Womersley number, ω ′ of 2.72 ≤ ω ′ ≤32.21 are presented. Instantaneous wall shear stress,)(tωτ is evaluated using the solution of time-dependent momentum integral equation. Instantaneous friction factor,)(tuλ, time-averaged friction factor, tau,λ and laminar quasi-steady friction factor,)(tqLλ are calculated in the devised program, TDFC.vi