The simulation of the annular flow of electrorheological fluid (ERF) is the actual task because this type of flow is applied to industrial devices (damper, shock absorber and etc). Rheological ERFs depend on electrical field strength. The purpose of this work is simulation of Bingham ERF flow in annular gap taking into account the inhomogeneity of electrical field strength. The results of flow curve analysis in some Bingham ERFs and own models which describe dependence between yield stress, plastic viscosity and electrical field strength have been presented. These models have been used at analytical solving of hydrodynamic problem. The obtained analytical solution allows to perform the hydrodynamic calculation of Bingham fluid flow in annular gap when yield stress and plastic viscosity depend on the inhomogeneity of electrical field strength.
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The purpose of this study was experimental investigation of hemorheological changes under photodynamic therapy. The experiments were conducted on laboratory white purebred male rats under narcosis. Chlorin e6 as photosensitizer (PS) was used. Photodynamic exposure (PDE) was performed with semiconductor laser (wave length 670nm). The irradiated area was , and light exposure dose E was 22.5 to . Blood was sampled 1 hour after PDE completion and was heparin-conserved. The experimental study of PDE effect on the rheological properties of blood of tumour-free rats revealed that chlorin at a dose of body mass caused a significant increase in the hematocrit H. The flow curves were adequately described by the power law rheological model with independent of H and E. The correction to the parameter of blood consistency K in rats not exposed to PDE assumed the form . The exposure of rat skin to light at E 22.5 to resulted in an increase in the consistency parameter. The flow curves taking into account PDE are adequately described by the model . The results obtained from this study indicate that PDE at a concentrated chlorin dose of and light exposure dose of 22.5 to produces a significant increase in rat blood non-newtonian viscosity.
The solution is given to a problem of non-steady (oscillating) flow of linear viscoplastic media in an annular gap of rotational viscometer: the outer cylinder moves stepwise, the inner one is fixed. It was shown that average shear rate on the surface of inner cylinder differed from its steady-state value by the factor t1/t2 (t1 is the motion length of time, t2 is the fall period of time).
PL
Przedstawiono rozwiązanie zagadnienia nieustalonego (oscylacyjnego) przepływu liniowych lepkosprężystych mediów w pierścieniowej szczelinie rotacyjnego wiskozymetru, w którym wewnętrzny cylinder porusza się skokowo, wewnętrzny zaś jest nieruchomy. Wykazano, że średnia prędkość ścinania na powierzchni wewnętrznego cylindra różni się od jej ustalonej wartości o czynnik t1/t2 (t1 jest czasem trwania ruchu, t2 - pełnym okresem czasu).
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