Break-up of Newtonian liquids

The experimental results using the above assumed value of are compared with the literature value for elongational flow. The measured d values were found to be 50 times lower than the literature value and this means that the actual saliva stress in the mastication process is 50 Pa. Under shear flow, there is a rapid increase in capillary number when q /q,. 1. 

The break-up of Newtonian liquids with various viscosities t] can be investigated by mastication of small oil samples and measuring the resulting droplet size distribution, using a Coulter Counter or a Master sizer. Samples are expectorated into a suitable surfactant solution, e.g. Tween (to prevent coalescence during measurements). can be measured at 37 °C (body temperature) using a suitable rheome- 

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