Three­dimensional Tomographic Reconstruction for Analysis of Droplet Behaviors from Electrohydrodynamic Jet

Chao Chen1, Yong­Jae Kim2, Soo­Hong Lee1, Seung­Bae Kim1 and Han Seo Ko1

1 School of Mechanical Engineering, Sungkyunkwan University, Suwon, Korea, hanseoko@skku.edu

2 School of Information and Communication Engineering, Sungkyunkwan University, Suwon, Korea

ABSTRACT

Droplet behaviours ejected from an electrohydrodynamic (EHD) jet have been analyzed by performed experiments initially. Since the droplet shape is not axisymmetric and the droplet does not go straight, three­dimensional tomography techniques have been developed as an effective tool in order to investigate the size, location, and shape of the droplets in this study. Computer­synthesized phantoms for liquid meniscus with one and two small droplets have been reconstructed by four three­dimensional tomography methods such as an algebraic reconstruction technique (ART), an adaptive algebraic reconstruction technique (AART), simultaneous iterative reconstruction technique (SIRT) and a multiplicative algebraic reconstruction technique (MART) to obtain accurate results for the droplet movements using the multiple projection angles of view. Four different basis functions including cubic B­spline basis function, cubic cosine basis function, cubic o­Moms basis function and keys basis function have been adopted to improve the performance of the developed tomographic reconstructions. From comparison of the four tomography results, the MART method with the cubic cosine basis function provides a significant improvement in the reconstruction accuracy for analysis of the droplets. In addition, the four different tomography methods with the aforementioned basis functions have been confirmed using experimental projection data obtained from two high speed cameras in two projection angles of view.

Keywords Droplet, Electrohydrodynamic, Tomography, Basis function