--- _id: '6486' abstract: - lang: eng text: Based on a novel control scheme, where a steady modification of the streamwise velocity profile leads to complete relaminarization of initially fully turbulent pipe flow, we investigate the applicability and usefulness of custom-shaped honeycombs for such control. The custom-shaped honeycombs are used as stationary flow management devices which generate specific modifications of the streamwise velocity profile. Stereoscopic particle image velocimetry and pressure drop measurements are used to investigate and capture the development of the relaminarizing flow downstream these devices. We compare the performance of straight (constant length across the radius of the pipe) honeycombs with custom-shaped ones (variable length across the radius) and try to determine the optimal shape for maximal relaminarization at minimal pressure loss. The optimally modified streamwise velocity profile is found to be M-shaped, and the maximum attainable Reynolds number for total relaminarization is found to be of the order of 10,000. Consequently, the respective reduction in skin friction downstream of the device is almost by a factor of 5. The break-even point, where the additional pressure drop caused by the device is balanced by the savings due to relaminarization and a net gain is obtained, corresponds to a downstream stretch of distances as low as approximately 100 pipe diameters of laminar flow. acknowledged_ssus: - _id: M-Shop article_number: '111105' article_processing_charge: No article_type: original author: - first_name: Jakob full_name: Kühnen, Jakob id: 3A47AE32-F248-11E8-B48F-1D18A9856A87 last_name: Kühnen orcid: 0000-0003-4312-0179 - first_name: Davide full_name: Scarselli, Davide id: 40315C30-F248-11E8-B48F-1D18A9856A87 last_name: Scarselli orcid: 0000-0001-5227-4271 - first_name: Björn full_name: Hof, Björn id: 3A374330-F248-11E8-B48F-1D18A9856A87 last_name: Hof orcid: 0000-0003-2057-2754 citation: ama: Kühnen J, Scarselli D, Hof B. Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. Journal of Fluids Engineering. 2019;141(11). doi:10.1115/1.4043494 apa: Kühnen, J., Scarselli, D., & Hof, B. (2019). Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. Journal of Fluids Engineering. ASME. https://doi.org/10.1115/1.4043494 chicago: Kühnen, Jakob, Davide Scarselli, and Björn Hof. “Relaminarization of Pipe Flow by Means of 3D-Printed Shaped Honeycombs.” Journal of Fluids Engineering. ASME, 2019. https://doi.org/10.1115/1.4043494. ieee: J. Kühnen, D. Scarselli, and B. Hof, “Relaminarization of pipe flow by means of 3D-printed shaped honeycombs,” Journal of Fluids Engineering, vol. 141, no. 11. ASME, 2019. ista: Kühnen J, Scarselli D, Hof B. 2019. Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. Journal of Fluids Engineering. 141(11), 111105. mla: Kühnen, Jakob, et al. “Relaminarization of Pipe Flow by Means of 3D-Printed Shaped Honeycombs.” Journal of Fluids Engineering, vol. 141, no. 11, 111105, ASME, 2019, doi:10.1115/1.4043494. short: J. Kühnen, D. Scarselli, B. Hof, Journal of Fluids Engineering 141 (2019). date_created: 2019-05-26T21:59:13Z date_published: 2019-11-01T00:00:00Z date_updated: 2024-03-27T23:30:35Z day: '01' department: - _id: BjHo doi: 10.1115/1.4043494 ec_funded: 1 external_id: arxiv: - '1809.07625' isi: - '000487748600005' intvolume: ' 141' isi: 1 issue: '11' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1809.07625 month: '11' oa: 1 oa_version: Preprint project: - _id: 25152F3A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '306589' name: Decoding the complexity of turbulence at its origin publication: Journal of Fluids Engineering publication_identifier: eissn: - 1528901X issn: - '00982202' publication_status: published publisher: ASME quality_controlled: '1' related_material: record: - id: '7258' relation: dissertation_contains status: public scopus_import: '1' status: public title: Relaminarization of pipe flow by means of 3D-printed shaped honeycombs type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 141 year: '2019' ...