a Liquid honey is a fluid having a high viscosity which decreases significantly as its temperature increases It is proposed to measure the viscosity of honey at T=30C which is a value close to natural bee temperature habitat and a maximum operating limit of honey processing by growers. Measurements are done by comparison to reference viscous liquid : glycerol of known viscosity which happens to be close to that of honey. A The method consists in measuring the duration Ar of a laminar flow of a given mass of honey (m) flowing form an upper reservoir to a lower one through a narrow tube (radius R, length L, and extremities A to B). All different parts of the device are thermally isolated to insure a constant T=30C throughout the experiment (isolation not represented in the figure and temperature is controlled in the two reservoirs). Gravity flow B B HE (note that numerical values are given in question 3). 1. Assuming laminar flow, according to Poiseuille's law, friction losses inside the tube (of length 8.v.. L) is given by : = r.p.R - v is the fluid's volume flowrate -pis the density, -u is the viscosity Recall units of all parameters: L,R, ,, , . 2. (a) Write down the applicable energy equation between points A and B ? m.Rg J.V (b) Assuming that the pressures at the two extremities (A and B) are almost equivalent (PA ** De Putm), verify the following relationship: 8 P 3. (a) Following some measurements at 30C we get : Honey p=1.41 g'cm': masse transferred m = 12.30 g in AX = 2 min. glycerol: p=1.26 g'cm: masse transferred m' = 11.45 g in Ar' = 1 min compute the volume flowrates V and V for both fluids (b) If the viscosity for glycerol at 30C is ui' = 0.63 Pars, estimate the viscosity for honey