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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.

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This article summarizes the results of computer simulation of the air flows in the nasal cavity and the maxillary sinus by the computational fluid dynamics (CFD) method. The objective of the study was to apply the method of computational aerodynamics to simulate the air flows in the nasal cavity and the maxillary sinus under the normal conditions and after the surgical interventions on the middle nasal meatus. The normal air space of the nasal cavity and paranasal sinuses was simulated and the computer modeling of the main options for the surgical approach to the maxillary sinus through the middle nasal meatus was performed including balloon sinuplasty, functional endoscopic sinus surgery, and uncinate process mobilization. The study has demonstrated the increase of the air flow velocity in the maxillary sinus after computer-assisted balloon sinuplasty. The computer simulation of functional endoscopic sinus surgery including the removal of the uncinated process revealed the mass exchange between the maxillary sinus and the nasal cavity.

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