Faculty: Dr. P. Wood

 


Dr. WoodAssociate V-P Student Affairs

Professor
Department of Chemical Engineering

McMaster University
1280 Main Street West, Hamilton
Ontario, Canada  L8S 4L7

office: GH 207
email: woodpe@mcmaster.ca
voice: (905) 525-9140 ext. 27455

B.A.Sc., University of Waterloo (1973), P.Eng., Ph.D. California Institute
of Technology (1978), F.C.I.C., P.Eng.

Research Interests

Fluid Mechanics and Heat Transfer

The main focus of my work is fluid mechanics and heat transfer with particular
emphasis on mixing problems. The projects have both theoretical and experimental
components.

1. Static Mixers and Twin Screw Extruders

In this project we propose to study mixing in a Kenics type static mixer and the intermeshing
twin screw extruder. A Kenics static mixer is a series alternating right handed or left handed
twisted tapes or elements. In the standard design each element twists through 180 degrees
and each successive element is off-set by 90 degrees. As the fluids to be mixed pass through
the mixer they are periodically separated and rotated, reducing the scale of segregation or
"striation thickness" with each successive element. The objectives of this research will be
to: (1) create a data base of velocity measurements (axial, radial and tangential) in a static
mixer as a function of aspect ratio, Reynolds number and flow rate ratio, (2) develop a visual
technique for measuring striation thickness in a Kenics static mixer, (3) develop a measure
of mixing that can be used to characterize the degree of mixedness in a static mixer, and (4) use computational fluid dynamics to compute the velocity field for comparison with the measured
velocities.

2. Mixed Convection Heat Transfer

Mixed convection flow and heat transfer occur frequently in engineering and natural situations.
One important application occurs when a heated surface is cooled by a flowing fluid where
the flow may be in the direction of, or opposed to, the gravity vector. In this research project
we propose to carry out a fundamental experimental and computational study of mixed
convective flow. The objectives of the study will be to: (1) create a data base of velocity
and temperature measurements in a well characterized geometry ( a heated wall cavity),
(2) apply the PIV technique to these flows and validate its use by comparison to other
experimental measurements, (3) develop a low Reynolds number turbulence model which
accounts for the inherent anisotropy of the turbulence, and (4) to develop a new numerical
solution algorithm which allows for a closer coupling between the temperature and velocity
fields than the presently used SIMPLE based methods.

3. Suspension Polymerization

In suspension polymerization liquid monomer droplets are dispersed in water. During
the period of the polymerization the droplets become solid. The droplets are maintained in
suspension and coalescence is prevented by the combined action of mixing and surface
active agents. These will also affect the particle size distribution (PSD). The ability to
predict and control the PSD is of considerable importance to the polymer industry. The
principal goal of this research will be to develop a mathematical model for the estimation
and design of the polymer PSD obtained in suspension copolymerization.

Selected Publications

Vivaldo Lima, E., A.E. Hamielec and P.E. Wood, "Auto Acceleration Effect in Free Radical
Polymerization. A Comparison of the CCS and the MH Models", Polymer Reaction
Engineering, 2, 17-86, (1994).

Nurnberg, G., P.E. Wood and M. Shoukri, "Experimental and Numerical Turbulent Bouyant
Flow in an Enclosure"', 10th Int. Heat Transfer Conf., England, 7, 119-124, (1994).

Kresta, S.M. and P.E. Wood, "The Flow Field Produced by a 45ø Pitched Blade Turbine:
Characterization of the Turbulence and Estimation of the Dissipation Rate", Chem. Eng.
Sci., 48, 1761-1774, (1993).

Wood, P.E., A.N. Hrymak, R.W. Yeo, D.A. Johnson, and A. Tyagi, "Experimental and
Computational Studies of the Fluid Mechanics in an Opposed Jet Mixing Head", Physics
of Fluids A, 3, 1362-1368, (1991).