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When the motion vectors of the media are collinear, well-known experimentally obtained empirical criteria are used to assess the conditions for the drop entrainment by the gas flow from the surface of a moving liquid film. However, blowing a liquid film at an angle with gas causes a tangential component in the film movement, which is an additional factor affecting its thickness and the velocity profile. The paper presents the correctness of the criterion of the conditions for the drop entrainment and the effect of the noncollinearity of the vectors of the media counterflow on the dynamics of a liquid film estimated from the results of numerical simulation.

The present paper compares, for the first time, the regimes of a pulsating turbulent flow in a smooth pipe in terms of 0.001 ≤ ω+ ≤ 0.0346 and 0.16 ≤ β ≤ 0.63 at Re ≈ 7000 with the uncertainty in estimating the flow rate by an ultrasonic flowmeter. It was revealed that the classification of pulsating flow regimes according to the dimensionless angular frequency ω+ does not have a direct relation with the K parameter equal to the ratio of the phase-average calibration constant in pulsating flow to the corresponding value in steady flow. The results of data processing showed that K depends on the relative amplitude of pulsations β and the position of the chord of the ultrasonic beam trajectory (L/R is distance L from the pipe center to the chord to the pipe radius R). In the coordinates β and L/R, there is a rather wide area where the uncertainty in flow rate estimation of pulsating flows should not exceed 0.5%. An increase in β or L/R leads to an increase in measurement uncertainty, which in the limiting case β, L/R → 1 can reach 5% or more. Favorable and unfavorable areas of the pipe section were identified when scanning pulsating flows and the effectiveness of using multi-path scanning schemes was estimated to reduce the resulting effect of flow pulsations on flow measurement uncertainty.

The flow structure in a turbulent double-cavity flow has been studied experimentally and numerically. The dynamics of the two-component instantaneous velocity vector fields measured by an optical smoke image velocimetry method and calculated using the ANSYS Fluent 19.2 software has been derived. For a wide range of dynamic similarity numbers of shape factor and ReL, the flow resistance coefficients for the cavity and relative flow mass transfer with the cavities have been estimated; three characteristic flow regimes of double-cavity flow have been distinguished and described; the flow pattern map via the ReL number and shape factor has been obtained.

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The experimental data on the flow rate (velocity) of a fluctuating air flow are presented on a wide fluctuation frequency range at a constant pressure difference between the channel entry and exit. The superimposed flow fluctuations were produced by periodic cut-off of the exit section by a rotating damper. A considerable dependence of the mean flow rate (velocity) on the wave structure of the flow is established. A flow rate minimum corresponds to resonance flow modes with a maximum relative amplitude of the flow velocity fluctuations.