Heat transfer during laminar flow in a vertical annular channel with a constant temperature of the outer wall

Developed flows during combined convection in a vertical concentric annular channel are discussed. The problem is solved for descending and ascending flows. A dimensionless equation is obtained for calculating the value of the heat-transfer coefficient averaged over the length of the channel.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 33, No. 1, pp. 11–16, July, 1977.     

Increasing the rate of heat transfer in ducts with a turbulent gas flow

Results are shown of a study concerning the heat transfer and the hydraulic drag in an air stream through ducts of various shapes with wavy rough walls and with boundary-layer breakers.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 22, No. 6, pp. 981–986, June, 1972.     

Transformation and intensification of tornado-like flow in a narrow channel during elongation of an oval dimple with constant area

Technical Physics Letters - Reynolds averaged Navier–Stokes equations closed using the Menter shear-stress-transfer model have been numerically solved on multiblock intersecting structured...     

Volumetric rate of a turbulent newtonian fluid flow in a cylindrical channel

A new formula to calculate the volumetric rate of a turbulent Newtonian fluid flow is suggested. Experimental verification of the validity of the formula for fluids of different physicochemical nature passed through a cylindrical channel of a laboratory rig has been made. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 5, pp. 856–859, September–October, 2008.     

Pressure loss during fluid flow in a channel rotating perpendicularly to the axis of rotation

Results are presented which were obtained in experiments to determine the hydraulic resistance of a channel during its rotation around an axis perpendicular to the channel axis.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 29, No. 6, pp. 1024–1030, December, 1975.     

A study on the pumping performance of the disk-type drag pumps for spiral channel in rarefied gas flow

The pumping characteristics of a single-stage disk-type drag pump (DTDP) are calculated for the variation of the vertical clearance between a rotor and stator by the three-dimensional direct simulation Monte Carlo method. The gas flow mainly belongs to the molecular transition flow region. Spiral channels of a DTDP are cut on both the upper and lower sides of rotating disks, but the stationary disks are planar. The interaction between molecules is described by the variable hard-sphere model. The no-time counter method is used as a collision sampling technique. As a consequence of results, the vertical clearance between a rotor and stator has a significant effect on the pumping performance. Experiments are performed under the outlet pressure range of 0.4-533 Pa. When the numerical results are compared to the experimental data, the numerical results agree well qualitatively.     

A three-dimensional model for flow pumping in a microchannel inspired by insect respiration

We present a three-dimensional model for flow pumping in a channel induced by two moving contractions from the upper wall. This pumping model is inspired by insect respiration processes, specifically, the rhythmic collapses that take place within their tracheal tube networks. The present work is a natural extension of our previous theoretical and numerical investigations of a two-dimensional insect-inspired micropumping model, which accounts for three-dimensional effects and further validates our insect-inspired pumping paradigm (Aboelkassem and Staples in Acta Mech 223(3):463–480, 2012a; Theor Comput Fluid Dyn, 2012b. doi:10.1007/s00162-012-0269-7). The formal goal of this article is to compare three-dimensional Stokeslets-meshfree numerical results with results from our previous two-dimensional analytical pumping model. We use regularized Stokeslets-meshfree computations in three dimensions to reconstruct the flow motions induced by wall contractions and to calculate the time-averaged net flow pumping rate. The results show that, although the net flow rate distribution as a function of the wall motion time (phase) lag parameter for the three-dimensional Stokeslets-meshfree computations and the two-dimensional analytical model displays some differences, the same basic features appear in both cases, leading to the same general conclusions about the proposed pumping paradigm.     

Impurity dispersion in the turner model for flow in a porous channel

A one-dimensional model for longitudinal diffusion in a capillary with an immobile layer is derived.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 27, No. 1, pp. 92–96, July, 1974.     

Fluctuations in the rate of flow during filtration of polymer solutions

This article demonstrates the possibility of a loss of stability in steady-state regimes involved in the filtration of polymer solutions, and we present also the construction of a mathematical model on the basis of whose analysis we have ascertained the unique features of self-oscillations and stochastic oscillations which arise in the region of instability.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 59, No. 2, pp. 211–215, August, 1990.     

Heat transfer enhancement of backward-facing step flow in a channel by using baffle installation on the channel wall

Summary. Aiming to enhance the heat transfer characteristics of backward-facing step flow in a channel, the present study proposes a method to install a baffle onto the channel wall. The effects of the dimensionless baffle height H_b, baffle thickness W_b, and distance between the backward-facing step and baffle D on the flow structure, temperature distribution and Nusselt number variation for the system at various Re and Gr/Re² are numerically investigated. Comparing the results of the cases with or without the installation of baffle, the maximum augmentation on average Nusselt number is about 190% for the heating step and 150% for the heating section of the bottom plate when Pr=0.7, H_s=0.5, L=5, H_b=0.3, W_b=0.2, 100 Re 500 and 0Gr/Re²1. A slight movement of the baffle position could cause a drastic change in the transfer characteristics. In addition, as W_b varies from 0.2 to 0.5, the difference in the average Nusselt number is within 3%.     

Equipment for monitoring the diaphragms used to measure flow rate by the variable pressure drop method

The results of measurements of the length of an end gauge and of the length of the cylindrical part of the orifice of a diaphragm, carried out on an instrumental microscope using a pentaprism, included in the set of equipment, are presented. __________ Translated from Izmeritel'naya Tekhnika, No. 1, pp. 25–26, January, 2006.     

Electrohydrodynamic pulsatile flow in a channel bounded by porous layer of smart material

Electrohydrodynamic dispersion due to pulsatile flow in a channel bounded by porous layer of smart material is studied considering both steady and unsteady cases using both BJ and BJR-slip conditions. We found that in the case of steady flow, the dispersion coefficient, decreases with an increase in electric number W_e but increases with an increase in porous parameter σ_p in the case of BJ-slip condition. However this nature is different in the case of BJR-slip condition in the sense that the dispersion coefficient, increases for certain values of W_e and then decreases with an increase in W_e. In the case of unsteady flow, the dispersion coefficient, , decreases with an increase in W_e and σ_p for both BJ and BJR conditions. In particular, we found that the value of for steady flow in the case of BJ-slip condition is less than that of unsteady flow. The opposite is true for BJR condition. The findings are useful in the design of robust and efficient artificial organs in the human body.     

Prediction of the relative divergence of flow rate measurement channel readings in problems of thermal energy accounting

An audit method for instrument metering of thermal energy is given. It is based on predicting the relative divergence of measured readings of heat carrier flow rate channels in a closed heat supply system. Ways of improving heat prediction reliability are suggested. __________ Translated from Izmeritel’naya Tekhnika, No. 4. pp. 35–39, April, 2008.     

Turbulent flow in a rectangular cavity in the wall of a two-dimensional channel

Results are presented of a theoretical and experimental investigation of flow of a turbulent incompressible liquid over a rectangular cavity of relative depth 1–3.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 46, No. 3, pp. 363–371, March, 1984.     

Longitudinal dispersion in the flow of a multicomponent mixture in a plane channel

The propagation of a multicomponent mixture in a channel is considered. An equation generalizing the well-known Taylor equation [1] both to the multicomponent case and so as to take account of the dependence of the transport coefficients on the concentrations of the components is obtained.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 56, No. 6, pp. 931–936, June, 1989.     

Micromixing models for calculating the average rate of a chemical reaction in a turbulent flow

A model of mixing with a chemical reaction in a uniform, isotropic turbulent flow has been developed on the basis of the statistical-moments method for calculating the hydrodynamic characteristics of a flow and the probability density function of its mixture coefficient for the purpose of determining the correlations responsible for the chemical reaction in the flow. The results of calculations of the average rate of a chemical reaction in a flow by the multizone model and models of micromixing (the mean-square approximation and Langevin models) used for construction of equations for the probability density function were compared.