Investigation of the effect of nozzle shape on supersonic/hypersonic impactors designed for size discrimination of nanoparticles--颗粒学报PARTICUOLOGY

Saadabadi, S., Abouali, O., Emdad, H., & Ahmadi, G. (2014). Investigation of the effect of nozzle shape on supersonic/hypersonic impactors designed for size discrimination of nanoparticles. Particuology, 16, 60–68. https://doi.org/10.1016/j.partic.2013.11.009

Investigation of the effect of nozzle shape on supersonic/hypersonic impactors designed for size discrimination of nanoparticles

Saeideh Saadabadi ^a, Omid Abouali ^a *, Homayoon Emdad ^a, Goodarz Ahmadi ^b

a School of Mechanical Engineering, Shiraz University, Shiraz, Iran
b Department of Aeronautical and Mechanical Engineering, Clarkson University, Potsdam, NY 13699, USA

10.1016/j.partic.2013.11.009

Volume 16, October 2014, Pages 60-68

Received 30 June 2013, Revised 27 October 2013, Accepted 29 November 2013, Available online 28 February 2014.

E-mail: abouali@shirazu.ac.ir; aboualio@yahoo.com

Highlights

• Different nozzle configurations were investigated for supersonic/hypersonic impactors.

• Using a cap as a focuser in the nozzle could decrease the cut-off size of impactor.

• Cone-cap nozzle performed better than disk-cap nozzle.

• Laval nozzle could have a small cut-off size if the nozzle was close to the impactor plate.

Abstract

In this study the flow field and the nanoparticle collection efficiency of supersonic/hypersonic impactors with different nozzle shapes were studied using a computational modeling approach. The aim of this study was to develop a nozzle design for supersonic/hypersonic impactors with the smallest possible cut-off size d₅₀ and rather sharp collection efficiency curves. The simulation results show that the changes in the angle and width of a converging nozzle do not alter the cut-off size of the impactor; however, using a conical Laval nozzle with an L/D_n ratio less than or equal to 2 reduced d₅₀. The effect of using a cap as a focuser in the nozzle of a supersonic/hypersonic impactor was also investigated. The results show that adding a cap in front of the nozzle had a noticeable effect on decreasing the cut-off size of the impactor. Both flat disks and conical caps were examined, and it was observed that the nozzle with the conical cap had a lower cut-off size.

Graphical abstract

Keywords

Supersonic/hypersonic; Impactor; Nanoparticle; Nozzle

文章导读