# MEEG636 Fluid Mechanics Measurements

TR 11 to 12:15; 109 Colburn

### INSTRUCTOR

Dr. Ajay K. Prasad

228 Spencer Lab

Office Hours: MW 10 - 11

### Topics to be covered

- Introduction to Measurements: Why we need experimentation, what
quantities do we measure.

- Measurable quantities: Mean, fluctuating components. Reynolds
decomposition for turbulent flow, turbulence closure problem.

- Error Analysis: How to improve experimental accuracy by optimal
choice of recording instrument.

- Flow Visualization: Addition of foreign materials to flow; optical
methods for compressible fluids.

- Differential pressure measurement: Pitot-static tube with
micromanometer for velocity measurement.

- Hot-Wire Anemometry: Constant Current vs. Constant Temperature
anemometers. heat transfer characteristics from wires. Linearization.
Sensitivity analysis, errors.

- Laser-Doppler Anemometry: Discussion of lasers, optics,
scattering from particles, electronic processing of Doppler signal,
sensitivity, error analysis.

- Particle Image Velocimetry: Particle Tracking, Youngs fringe
analysis, autocorrelation and cross-correlation analysis, diffraction
theory, holography.

- Statistics and Signal Processing: Stochastic processes, spectra,
correlation, time vs. frequency domains.

### Laboratory Experiments

Experiments will be conducted in groups of three. However, each
student will turn in a separate report. Students will perform a
minimum of four lab exercises to gain hands-on experience with the
following measurement techniques:

- Differential pressure anemometry
- Hot wire anemometry
- Laser-Doppler Anemometry
- Particle Image Velocimetry

Experiments pertain to the measurement of mean and rms velocity
profiles in turbulent pipe flow at a Reynolds number of 10,000, the
flow induced by an impeller in a continuously stirred tank
reactor (CSTR) and others.

### Term Paper

Each student will research a technique of his or her choice related to
fluids measurement, collect information from the library and
commercial vendors pertaining to that technique, assess the validity
of the technique and present their results in the form of a term paper
and an in-class Powerpoint presentation.