Sharif University of Technology Scientia Iranica 1026-3098 30 6 2023 11 01 CFD simulation of the laboratory-scale anaerobic digester to study the impacts of impeller geometric and operational parameters on its performance 2070 2081 23069 10.24200/sci.2022.59791.6444 EN M. E. Kashfi Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran 0000-0002-8457-0689 R. Kouhikamali - Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran - Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran G. Khayati Faculty of Chemical Engineering, University of Guilan, Rasht, Iran 0000-0003-3594-4266 J. Mahmoudimehr Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran Journal Article 2022 01 23 This research numerically surveys the effects of several main parameters of an agitated anaerobic digester on mixing rate and power input. The numerical simulation is handled applying the finite volume method (FVM), and it is validated with the available experimental data. The results indicate that doubling the blade length enhances the mixing rate by 39.9% and makes the power input enhance 13.5 times; increasing the number of blades (from 4 to 6) improves the mixing rate by 12.5% and makes the power input grow 1.4 times, and decreasing the blade tilt angle from 45° to 30° causes the mixing rate to drop by 14% and decreases the power input 1.8 times. Furthermore, the observations show that the mixing rate and power input are adversely influenced by the wastewater concentration. At last, the most effective impeller design, among 144 cases investigated, is found out and suggested. https://scientiairanica.sharif.edu/article_23069_4f3128981beda3364c8ff9cdb0a1b008.pdf