Volume 1 - Section IV - Experimental Work and Verification of CFD Methodology 
Page IV-3 
inside the cage. Air velocities and temperatures were measured with thermistor based BESS Lab 
air velocity sensors and type T thermocouples, respectively. Six air velocity sensors were placed 
approximately 2.5e-2m (1") above the bedding and uniformly spaced around the cage at this 
level. Six thermocouples were placed approximately 2.5e-2m (1") from each air velocity sensor 
at the same height. A Campbell 2 IX data logger with an AM416 Multiplexer collected cage 
sensor outputs. 
Exact sensor locations, cage dimensions, and cage locations within the wind tunnel are available 
from the drawings in the figures 4.01 to 4.13. 
4.1.13 Experimental Data Sets Considered 
There were nine series of experimental scenarios considered in this project: 
Series Set Base 
In this series of experiments, the tracer gas used to determine the ventilation rate was exclusively 
99.8 percent purity CO 2 , that was injected (and sampled) at a rate of 1 L/min into the cage. The 
approaching air impacted the cage in three different orientations: the parallel orientation, in that 
the tunnel air moved horizontally towards the front edge of the cage; the perpendicular 
orientation, in that the tunnel air moved horizontally towards the side of the cage; and the 
vertical orientation, in that the tunnel air moved vertically downwards towards the top of the 
cage. These three orientations are summarized in figures 4.01 to 4.03. In each orientation, the air 
velocities approaching the cage were 15, 20, 30, 40, 50, 60, 70, 80, 90 and 100 fpm (0.075, 0.10, 
0.15, 0.20, 0.25, 0.3, 0.35, 0.40, 0.45 and 0.5 m/s respectively). 
Series Sets One and Two 
It was decided that the injection rate of CO 2 utilized in series set base was too large in 
comparison with the likely gaseous generation rates from the mice in the actual physical case, 
and that the magnitude of the injection could affect the flow field conditions within the cage, i.e., 
the gas would no longer act as a tracer gas. Also, it was decided that the higher end of the 
velocity range chosen, i.e., 0.3 m/s (60 fpm) and above, was unlikely to be present in the animal 
room facility close to the cages. 
In series sets one and two therefore, the injection rate was reduced to more realistic levels, and 
the tunnel approach velocity range was clipped at 0.25 m/s (50 fpm). In both series set one and 
two, the injection (and sampling) rate was set at 100 mL/min: in series set one, the tracer gas 
used was 99.8 percent purity CO 2 ; in series set two, the tracer gas used was 4.99 ppm SF6. The 
tests ran at 15, 20, 30, 40 and 50 fpm (0.075, 0.10, 0.15, 0.20 and 0.25 m/s respectively). The 
parallel and perpendicular orientations were both considered. 
