In this work the design of experiments procedure using Taguchi
approach is implemented to study the effect of multiple heat exchanger
parameters on the performance of the concentric heat exchanger
with injector turbulators. The factors used to perform the
experiments and the levels are given in Table 2. The L16 orthogonal
arrays most suitable for this experimental study given these factors,
and levels was selected as experimental plan (Table 3). This
test is carried out according to this experiment plan and the results
of experiments are transformed into an S/N ratio (Table 3). These
ratios are then interpreted. The S/N ratios help the researchers to
find which ones of parameters used in the experiments are more
effective on the performance characteristics (Nu and DP). S and N
in the S/N (signal to noise) are the signal and the noise factor,
respectively. The signal factors are also called as controllable
parameters. These parameters (angle, diameter, number of holes,
etc.) and the levels are chosen by the researchers. The noise factors
can be described as external factors affecting outcome during the
experiments but unable to attend the experimental design. It is
called as uncontrollable factors (ambient temperature, humidity,
dust, etc.)