Matches in SemOpenAlex for { <https://semopenalex.org/work/W2022963523> ?p ?o ?g. }
Showing items 1 to 69 of
69
with 100 items per page.
- W2022963523 endingPage "312" @default.
- W2022963523 startingPage "267" @default.
- W2022963523 abstract "A cylindrical pipe facility with a length of 32 m and a diameter of 40 mm has been designed. The natural transition Reynolds number, i.e. the Reynolds number at which transition occurs as a result of non-forced, natural disturbances, is approximately 60 000. In this facility we have studied the stability of cylindrical pipe flow to imposed disturbances. The disturbance consists of periodic suction and injection of fluid from a slit over the whole circumference in the pipe wall. The injection and suction are equal in magnitude and each distributed over half the circumference so that the disturbance is divergence free. The amplitude and frequency can be varied over a wide range. First, we consider a Newtonian fluid, water in our case. From the observations we compute the critical disturbance velocity, which is the smallest disturbance at a given Reynolds number for which transition occurs. For large wavenumbers, i.e. large frequencies, the dimensionless critical disturbance velocity scales according to Re −1 , while for small wavenumbers, i.e. small frequencies, it scales as Re −2/3 . The latter is in agreement with weak nonlinear stability theory. For Reynolds numbers above 30 000 multiple transition points are found which means that increasing the disturbance velocity at constant dimensionless wavenumber leads to the following course of events. First, the flow changes from laminar to turbulent at the critical disturbance velocity; subsequently at a higher value of the disturbance it returns back to laminar and at still larger disturbance velocities the flow again becomes turbulent. Secondly, we have carried out stability measurements for (non-Newtonian) dilute polymer solutions. The results show that the polymers reduce in general the natural transition Reynolds number. The cause of this reduction remains unclear, but a possible explanation may be related to a destabilizing effect of the elasticity on the developing boundary layers in the entry region of the flow. At the same time the polymers have a stabilizing effect with respect to the forced disturbances, namely the critical disturbance velocity for the polymer solutions is larger than for water. The stabilization is stronger for fresh polymer solutions and it is also larger when the polymers adopt a more extended conformation. A delay in transition has been only found for extended fresh polymers where delay means an increase of the critical Reynolds number, i.e. the number below which the flow remains laminar at any imposed disturbance." @default.
- W2022963523 created "2016-06-24" @default.
- W2022963523 creator A5038299660 @default.
- W2022963523 creator A5049064613 @default.
- W2022963523 creator A5085654338 @default.
- W2022963523 date "1998-12-25" @default.
- W2022963523 modified "2023-10-16" @default.
- W2022963523 title "Laminar–turbulent transition in pipe flow for Newtonian and non-Newtonian fluids" @default.
- W2022963523 doi "https://doi.org/10.1017/s0022112098003139" @default.
- W2022963523 hasPublicationYear "1998" @default.
- W2022963523 type Work @default.
- W2022963523 sameAs 2022963523 @default.
- W2022963523 citedByCount "156" @default.
- W2022963523 countsByYear W20229635232012 @default.
- W2022963523 countsByYear W20229635232013 @default.
- W2022963523 countsByYear W20229635232014 @default.
- W2022963523 countsByYear W20229635232015 @default.
- W2022963523 countsByYear W20229635232016 @default.
- W2022963523 countsByYear W20229635232017 @default.
- W2022963523 countsByYear W20229635232018 @default.
- W2022963523 countsByYear W20229635232019 @default.
- W2022963523 countsByYear W20229635232020 @default.
- W2022963523 countsByYear W20229635232021 @default.
- W2022963523 countsByYear W20229635232022 @default.
- W2022963523 countsByYear W20229635232023 @default.
- W2022963523 crossrefType "journal-article" @default.
- W2022963523 hasAuthorship W2022963523A5038299660 @default.
- W2022963523 hasAuthorship W2022963523A5049064613 @default.
- W2022963523 hasAuthorship W2022963523A5085654338 @default.
- W2022963523 hasConcept C112766332 @default.
- W2022963523 hasConcept C120665830 @default.
- W2022963523 hasConcept C121130766 @default.
- W2022963523 hasConcept C121332964 @default.
- W2022963523 hasConcept C182748727 @default.
- W2022963523 hasConcept C196558001 @default.
- W2022963523 hasConcept C204561356 @default.
- W2022963523 hasConcept C294558 @default.
- W2022963523 hasConcept C57879066 @default.
- W2022963523 hasConcept C76563973 @default.
- W2022963523 hasConceptScore W2022963523C112766332 @default.
- W2022963523 hasConceptScore W2022963523C120665830 @default.
- W2022963523 hasConceptScore W2022963523C121130766 @default.
- W2022963523 hasConceptScore W2022963523C121332964 @default.
- W2022963523 hasConceptScore W2022963523C182748727 @default.
- W2022963523 hasConceptScore W2022963523C196558001 @default.
- W2022963523 hasConceptScore W2022963523C204561356 @default.
- W2022963523 hasConceptScore W2022963523C294558 @default.
- W2022963523 hasConceptScore W2022963523C57879066 @default.
- W2022963523 hasConceptScore W2022963523C76563973 @default.
- W2022963523 hasLocation W20229635231 @default.
- W2022963523 hasOpenAccess W2022963523 @default.
- W2022963523 hasPrimaryLocation W20229635231 @default.
- W2022963523 hasRelatedWork W1569403900 @default.
- W2022963523 hasRelatedWork W1975462685 @default.
- W2022963523 hasRelatedWork W2039049555 @default.
- W2022963523 hasRelatedWork W2061699749 @default.
- W2022963523 hasRelatedWork W2091009214 @default.
- W2022963523 hasRelatedWork W2111074972 @default.
- W2022963523 hasRelatedWork W4200082783 @default.
- W2022963523 hasRelatedWork W4310832293 @default.
- W2022963523 hasRelatedWork W2182726697 @default.
- W2022963523 hasRelatedWork W2461683336 @default.
- W2022963523 hasVolume "377" @default.
- W2022963523 isParatext "false" @default.
- W2022963523 isRetracted "false" @default.
- W2022963523 magId "2022963523" @default.
- W2022963523 workType "article" @default.