|
| << vorige |
Tijdschrift beschrijving
Alle jaargangen van het bijbehorende tijdschrift
Alle afleveringen van het bijbehorende jaargang
Alle artikelen van de bijbehorende aflevering
Details van artikel 17 van 17 gevonden artikelen
| Titel: |
The Effects of Bluntness and Orientation on Two-Dimensional Samplers in Calm Air |
| Auteur: |
Chung, I-Ping Dunn-Rankin, Derek |
| Verschenen in: |
Aerosol science and technology |
| Paginering: | Jaargang 19 (1993) nr. 3 pagina's 371-380 |
| Jaar: |
1993 |
| Inhoud: |
This article uses numerical simulation to investigate the effect of sampler bluntness, particle size, and sampler orientation on aspiration efficiency in calm air. The procedure is to first numerically solve the velocity field around the sampler in calm air and then to trace the particle trajectories and calculate the the aspiration efficiency. Two samplers are studied: a two-dimensional parallel plate and a two-dimensional blunt cylinder. The variation of aspiration efficiency with particle size shows two minima between two asymptotic values. When the samplers are facing upward, the asymptotic values are 1 for very small particles and the ratio of particle settling velocity to suction velocity for very large particles. At other orientations, the horizontal-facing and the downward-facing, the asymptotic value for large particles is 0. The sampler bluntness has an important effect in the region of particle size where there is competition between the particle inertia and the fluid drag force (i.e., 5 μm < d > 100 μm in our case). A blunt sampler always has higher aspiration efficiency than does a sharp-edged sampler in this region of particle sizes. For very small particles and very large particles, the aspiration efficiencies approach asymptotic values and the sampler bluntness has little effect. The results also show that the sampler orientation affects the predicted aspiration efficiency |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 17 van 17 gevonden artikelen
| << vorige |