The breakup of drops of chlorobenzene, dlchloroethane and ethyl bronude, which were falhng freely through water, was studled All observed breakages occurred dunng the oscdlatlon which followed the first sheddmg of a class III attached wake Secondary drops were produced from protruchng columns of hqmd wtnch were formed at both the front and rear of the drops The factors wluch govern the sues of these secondary drops are &cussed and empvlcal relationshIps are presented Theoretical predldlons of the hquld column diameter lmmedlately pnor to neckmg and of the rate of necking of the column are compared with expenmentally detennmed values lNTRODUCTlON There have been several mvestlgatlons mto the breakup of drops wluch were movmg relative to a surroundmg fluld, but most of these were concerned either uvlth drops m steady sheared motlon[l-%] or with drops which were falling through a gas[5-91 In the present paper the breakup of drops which are fallmg freely m a hquld is discussed Tlus breakup 1s caused by the natural oscdlatlons of the drops and occurs shortly after the drops have left the nozzle on which they are formed Most of the previously published mformation on tlus type of breakup 1s limited to isolated observations which were made durmg the study of other facets of drop hydrodynamlcs[lO-151 The only previous paper devoted to this subject was presented by Edge and Kalafatoglu [16] at the International Solvent Extraction Conference m 1974 and unfortunately the proceedings of tlus conference are not generally avadable Several authors have observed that large, freely-falhng drops may break up and Hu and Kmtner[l'l], followmg work done by Hmze [5] and Taylor[2], used a force balance to predict that for an mvlscld system (DE &,, the mmlmum drop diameter for breakup to occur, 1s mven by the equation W.C, = constant (1) which can be rewntten as (2) where K = 1452 x lo-* cm-' set* All previous workers have observed that breakup occurs a short &stance below the nozzle on wluch the drops are formed and Schroeder and KmtnerIlO] reported that It 1s caused by the oscdlations w&h are induced durmg detachment from the nozzle Elzmga and tPresent address TUBITAK-MAE. Kunya Biiliimii, PK141 KadGy.
Istanbul, Turkey