Summary
The study concentrated on understanding several aspects of impactors that were typified by round or rectangular nozzles. Specifically, the features of the impactors were determined using the numerical solutions that were based on the platforms of the Navier-Stokes equations. In addition, the equation that was used to solve problems of motion of particles was applied. To evaluate the sensitivity of the solution to the system in the context, the researchers utilized the approach of decreasing the number and sizes between them. The study established that the curves obtained were relatively sharp, implying that finer grids could be attained.
The study adopted a calculation strategy that was exemplified by an empirical ultra-Stokesian drag factor. The authors also noted that they used a facility for ensuring high levels of particle interceptions. It was concluded that important revisions were done in relation to the impactor theory, which included ultra-Stokesian equations aimed at producing the best results of dragging particles.
In fact, the revisions led to about 5% to 10% shifts in efficiency curves that were associated with inertial impactors. It was also concluded that the tail that was formed as a result of particle interception helped to decipher that it could not be significant enough to account for the variations in the experiment and theory. Finally, the authors concluded that the collection coefficient was shifted to the right by the impact of the ultra-Stokesian drag factor. Although the shift was relatively small, it was typical for impactor systems, but noticeable variations can be observed when higher frequencies are involved in relatively high Reynolds numbers.
Critique
From the article, it is evident that the authors provided a good background of the aspects they were investigating. In fact, they cited numerous studies that were conducted previously with the view of supporting their scientific suggestions. However, it is notable that they relied too much on theoretical studies rather than experiments, which are believed to yield better findings that can be tested in the laboratory.
The researchers did not indicate the number of samples that they handled. The sample size is a critical component in studies since it greatly impacts research findings. In the absence of sample size, it could be difficult for one to agree with the results. In addition, a full description of the methods and procedures adopted in the study was not provided, which leaves readers to assume what was done. That notwithstanding, the findings of the study would have important implications for researchers in aerosol science and technology.
Reference
Rader, Daniel J., and Virgil A. Marple. “Effect of ultra-Stokesian drag and particle interception on impaction characteristics.” Aerosol Science and Technology 4.2 (1985): 141-156.