Wake Velocities and Pressure Fluctuations in the Bistable Flow Behind Two Cylinders
Description
Data result from simultaneous measurements with two hot wires and two microphones in an aerodynamic channel with a rectangular cross section of 0.147 m x 0.193 m and acrylic walls to study the wake behavior after a pair of fixed cylinders. The two circular cylinders were made of commercial PVC tubes (Polyvinyl chloride) with a diameter of 25.1 mm, and a pitch-to-diameter ratio p/d = 1.26, resulting in a blockage ratio of 13%. The Reynolds numbers were Re = 1.06x104, Re = 2.16x104 and Re = 2.57x104, defined with the reference velocity (respectively: 10.05 m/s, 15,51 m/2 and 16.1 m/s) and the tube diameter. Reference velocity was measured by a Pitot tube at the test section entrance. The turbulence intensity at the test section was about 1%. Wake flow velocity was measured with a DANTEC StreamLine Constant Temperature Anemometer system with two DANTEC 55P11 probes aligned with the cylinders. Pressure fluctuation time series were measured using two 1/8” diameter condenser microphones (Brüel & Kjaer, Type 4138) flush-mounted with the channel walls in the wake region behind the cylinders. The microphones assembly includes pre-amplifier, conditioner, and an energy source. Data acquisition was performed by a USB 16-bit NI USB-9162 A/D board, sampling frequency 3000 Hz, low pass filter 1000 Hz, 131,072 samples, time series 43.690 s long. The uncertainties of the velocity measurements are about 3% and for the pressure 8.5%. Probes and microphones were enumerated 1 and 2. Microphone 1 was in a corresponding position to probe 1, and microphone 2 with probe 2. Time series of pressure fluctuations were generated separately from velocity series but simultaneously. Velocity series files - according to the Reynolds number: Velocity signals from the hot wire anemometers (m/s) – Time (s); velocity Probe 1 (u1); velocity Probe 2 (u2). Re_10600_Velocity.txt Re_21600_Velocity.txt Re_25700_Velocity.txt Pressure fluctuation files - according to the Reynolds number: Pressure fluctuations signals from condenser microphones [Pa] – Time (s); Pressure Microphone 1 (P1); Pressure Microphone 2 (P2). Re_10600_Pressure.txt Re_21600_Pressure.txt Re_25700_Pressure.txt Data are in .txt format to be read by almost all software.
Files
Steps to reproduce
Data are in .txt format to be read by almost all software.