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Edge Effects in Rotational Viscometry VI. ZZ- and KK- Type Sensors: No-slip Pseudosimilarity for Inertialess Flow (Revisited)
Wein, Ondřej ; Havlica, Jaromír
This report should serve as a manual to the program Prog_cL_m.exe for calculating the correction cL on edge effects in narrow-gap rotational viscometry with almost cylindrical or conical spindles. Referring to the previous Research Report ICPF 2004/8, which deals with the same subject, it includes, in addition, also computation of cL for the entire ZZ and KK sensors with an arbitrary front of bottom semi-sensors (FLAT, CONE, HUB, HAAKE). Detailed attention is paid to numerical aspects: extrapolation/interpolation of the related fields (angular velocity, shear stress, dissipation, local torque contribution) towards the boundaries, including the analytical smoothing at singularities. The source codes for Prog_cL_m.exe, the results of numerical simulations, as well as the resulting correlations for cL , are available on the attached CD, which is an integral part of this report. The inertia effect was computed using commercial software FLUENT 12 for the Z40DIN sensor and applied in an approximate way also for the KK35/23 sensor.
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Koncové efekty v rotační viskometrii za přítomnosti zdánlivého skluzu
Wein, Ondřej ; Večeř, Marek ; Havlica, Jaromír
Common methods of treating primary data from rotational viscometry are tested using numerical simulations of primary circular flow of shear-thinning liquids in an actual sensor Z40 DIN according to ISO 3219 and a new KK (Morse-taper) sensor, suggested for rotational viscometry under slip effect. Theory of the sensors is presented, including the conversion of primary data into fluidity and slip viscometric material functions, as well as a statistical analysis of their relevance. The data treatment, based on the concept of local filtration, is illustrated on several aqueous solutions of Hercules CMC and Welan gum.
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Hranové efekty v rotační viskozimetrii III. ZZ a KK sensory, psudopodobnost totálního skluzu
Wein, Ondřej
The edge effects in AWS rotational viscometry are studied for materials, displaying the total slip at walls, i.e. negligible effect of the bulk shear flow. The found analytic asymptotes correspond to two asymptotic flow behaviour – for Newtonian liquids and ideal plastic materials. The explicit formulas on the edge-effect correction cL for this constitutionally extreme case are given for the ZZ40 according to ISO 3219 (1994) standard and the novel KK35/23 configuration of our own design.
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A Novel Viscometric Sensor for Measuring the Apparent Wall Slip Effect
Wein, Ondřej ; Večeř, Marek
In the present lecture, heory is given of a viscometric experiment for the liquids displaying the apparent wall slip effect. A software package for treating the viscometric data from HAAKE RheoStress rotational theometers is presented. Using of the theory to calibration with a Newtonian liquid and the concept of local data filtering are illustrated on new experimental data.
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Hranové efekty v rotační viskozimetrii. I. Systém válec-válec (Couette), newtonské kapaliny
Wein, Ondřej ; Večeř, Marek
Exact calibration factors for a series of commercially available rotational viscometers are determined by solving the related elliptic boundary-value problem for the rotational flow of Newtonian media under zero Reynolds number (creeping flow approximation). In particular, the edge-effect correction for the Z40 DIN sensor (coaxial cylinders) should be 1.085 instead of incorrect 1.100, given in the related international standard ISO 3219 (Coaxial cylinders for liquids of medium viscosity). The edge-effect correction was determined also for a new KK sensor (coaxial Morse cones) in dependence of the adjustable gap thickness.
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