P. Ya. Belousov

A method for measuring the size distribution and the local gas concentration in gas-liquid flows

A new optical method for measuring sizes of a dispersed phase (gas bubbles in liquid or drops of liquid in gas) illuminated by a laser “sheet” is substantiated theoretically and experimentally. The accuracy of the method is determined by the resolution of image recording systems. In a test experiment, the error for measuring the sizes of a dispersed phase was under 1%.

Measurement of the radius and slip velocity of a rolling wheel by a laser Doppler anemometer

The use of laser Doppler anemometry methods for determining the radius and slip velocity of rolling wheels is justified theoretically and experimentally. It is demonstrated that these methods allow the wheel radius to be measured with a relative error of 0.05–0.02% for the wheel turning angle of 0.6–4.0°. The slip velocity can be calculated in this case with an error of 20%. The slip velocity of a railroad wheel moving with a velocity of 60 mm/s is found.

Laser Doppler chromatic imaging of rotating structures

A method of the flow field velocity monitoring has been developed based on the laser Doppler imaging with chromatic selection of the velocity vector components in an orthogonal coordinate basis set.

Determination of the velocity and size of bubbles in two-phase flows by using a laser doppler anemometer

Natural oscillations of a spherical interface between a gas and a liquid in a bubble are registered. A possibility of measuring the geometric parameters of stationary and moving particles of the disperse phase by a laser Doppler anemometer is demonstrated. A method for simultaneous determination of the size and velocity of a bubble or a droplet in a two-phase flow is developed. The mean sizes of a group of bubbles settled on a ruler are compared: the results are obtained by two independent methods, i.e., by analyzing the image and by processing the Doppler signal containing information about the natural oscillations of the spherical interface between the media. A possibility of using a laser Doppler anemometer for simultaneous measurements of the velocity and size of bubbles or droplets in a two-phase flow is confirmed.

Optical control of the radius of a wheel rolling on a rail

An optical method for measuring the geometric radius and velocity of slip of a wheel rolling on a rail is discussed.

Measuring the Shape of Cylindrical Samples by the Laser Doppler Method

An optical method for measuring the shape of the normal guide bearing of a solid uniform cylindrical sample is presented (the guide bearing lies in the plane orthogonal to the cylinder elements). The method is based on measuring the linear speed of a cylinder, which is rolling over plane guides. The possibility of measuring small deviations (a few microns for a 10-mm-diameter cylinder) of the bearing from the circular shape is demonstrated. The reliability of results is verified by micrometric measurements of the diameter. The shape of the guide of a solid cylindrical roller from the 3ГП 3 roller bearing with a diameter of 9 mm was measured as an example. It is shown that the guide bearing shape is approximately sinusoidal with a period of 2π and an amplitude of periodical variations of ±1.5 μm.

Measurement of bubble and droplet diameters by the Doppler anemometry

Interaction of a probing laser beam with a liquid droplet is analyzed theoretically. It is shown that the amplitude of the Doppler signal obtained from a moving droplet depends on its position with respect to the beam waist. The possibility of determining the radii of droplets and bubbles moving in the flow from the spatial positions of the extreme points of the Doppler signal amplitude is justified theoretically and experimentally. The radius of glass spheres is measured (1.75 and 5 mm). The relative error of measurements is 1.1 and 8%. The radius of bubbles upfloating in a viscous liquid is measured. It is shown that the proposed method based on the Doppler anemometry offers prospects in studying two-phase flows.

Optical diagnostics of gas-droplet flows

A gas-droplet flow generated by a pneumatic injector with internal mixing is studied by optical methods. The fractional composition and the spatial distribution of liquid droplets for different fractions are measured, as well as the mean velocity field.

Measuring the thickness of the fluid film moving on a spherical surface

The dependence of the thickness of the fluid film flowing down the sphere surface in the gravity field on the fluid flow rate and the polar coordinate is measured by an optical method. Comparisons of experimental data with theoretical estimates are demonstrated.

Measurement of noncircularity of cylinders freely rolling on directing supports or a smooth surface

A new optical method of measuring noncircularity of cylinders is experimentally justified. The method is based on measuring the horizontal projection of velocity of a rolling circular body and calculating the maximum deviation of the local radius periodically repeated in the course of motion. Results measured by the proposed method are compared with direct measurements by a micrometer. The new method allows estimating tolerances of noncircularity in the case of defects of cylinder generatrices and the maximum variations of the radius in the case of guideline noncircularity. The noncircularity measurement error (∼1 µm) is experimentally verified.