Residence time distribution analysis from a continuous couette flow device around critical taylor number

This paper presents an experimental study of residence time distribution (RTD) analysis by pulse response technique in a continuous Couette flow device with rotating inner cylinder and stationary outer cylinder. Two kinds of experimental tests using pulses of tracer dye solution and particles resulting from a fast precipitation were performed in the region near the critical Taylor number characterizing boundary between laminar and laminar vortex flow. For most experiments performed in laminar and laminar vortex flow regime around the critical Taylor number over the ranges 0 < Ta < 120 and 0 < Re < 5.5 the normalized response can be described by a dispersion model. The results of the critical Taylor number as characterized by the minimum dispersion number appear consistent with both theoretical predictions and other empirical observations. On presente une etude experimentale sur ľanalyse de la distribution du temps de sejour par la technique de reponse aux impulsions dans un dispositif ďecoulement continu Couette muni ďun cylindre interne rotatif et ďun cylindre externe fixe. Deux types ďexperiences utilisant des impulsions ďun marqueur colore et de particules issues ďune precipitation rapide ont ete menees dans la region proche du nombre de Taylor critique qui caracterise la frontiere entre ľecoulement laminaire et ľecoulement laminaire tourbillonnaire. Pour la plupart des experiences realisees en regime laminaire et en regime laminaire tourbillonnaire autour du nombre de Taylor critique dans les gammes 0 < Ta < 120 et 0 < Re < 5,5, la reponse normalisee peut ětre decrite par un modele de dispersion. Les resultats du nombre de Taylor critique exprime par le nombre de dispersion minimum semblent en accord avec les predictions theoriques et les autres observations empiriques.