The Design And Validation of a Calibration Jet for Five-hole Pressure Probes

Open Access
Author:
D'imperio, Mark Francis
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Stephen P Lynch, Thesis Supervisor
  • Hosam Kadry Fathy, Honors Advisor
Keywords:
  • Five-hole probes
  • calibration
  • probes
  • air-jet
  • multi-hole probes
  • pressure probes
Abstract:
A five-hole probe is a unique measuring device that can provide information on a flow field’s three dimensional velocity vector. Many laboratories studying turbomachinery can utilize these probes to gather important information on complex flows that CFD software cannot always provide accurately. However, these probes can be difficult to calibrate and many laboratories do not have the capability of running their own calibrations. Often, they have to rely on the manufacturer’s original calibration which can become inaccurate over time. This thesis presents the construction and validation of a five-hole probe calibration system. The calibration system designed in this research produces an air-jet in which the velocity and pressure can be measured by pressure taps built into the sides of the rig’s piping. The system involves a series of pipes with a section of packed straws and three screens to reduce turbulence and straighten the flow in the system. To handle the probe’s position and orientation, a traverse and rotary table system was built to control the probe both manually and through automation. The probe can then be orientated at various pitch and yaw angles to gather calibration data in the air-jet. This thesis demonstrates calibration runs for the intended use of the probe at Re≈4842. After running repeated tests it was determined that the probe could produce reliable data for ranges of ±10o at this Reynold’s number. Having the system in the lab also gives the ability to recalibrate the probe for other values for Re which may have other ranges of useable data.