The spraying process simulation of the low-volume sprayer working body

The article presents the developed mathematical models that describe the process of spraying the working body of a low-volume sprayer. Theoretical studies show that with an increase in the supply of working fluid to the atomizing disc, the rotational speed of the pneumatic disc atomizer decreases, and in order to ensure the effect of the air flow on the droplet formation process, the radius of the disc should be larger than the radius of the base of the cone-shaped fairing, but less than its maximum critical value and for obtaining a monodisperse spray with the main droplet diameter d = 80 … 120 μm, at an axial air flow velocity of the fan installation U = 40 … 60 m/s, the parameters of the disk the sprayer and the propeller are linked together when the following values: disk radius r = 65 … 85 mm, the number of radial channels on the disk nр = 2 … 6 pcs, the width of the radial channel bр = 3 … 4 mm, and to obtain a high-quality air-droplet flow, the initial velocity of the main drops discharged from the periphery of the spraying disc must be less than the speed of the air flow and, at the same time, the rotational speed of the pneumatic disc sprayer is recommended to be used in the range of ω = 60… 200 s-1.

Validation of the Fast Neutron Field in the Radial Channel of the VR-1 Reactor

This work aims to characterize the neutron spectrum in the beam going out of the university research reactor (VR-1) using tubular-type of the nuclear fuel, version 4M (IRT-4M) fuel. Thanks to its variability, the core is often rearranged to fulfill different research tasks. Measurements with new core configuration have been carried out to confirm the spectrum shape in the neutron beam of the radial channel remains unchanged even though the core has been rearranged. Based on this finding, the VR-1 can be considered as a mockup for other IRT-4M fueled reactors, even with higher power. The neutron spectrum stability has been proven by measurement and by comparison of measurements done on the C12 and C13 cores. Fast neutron spectrum in the channel has been evaluated by means of neutron spectrometry by scintillation detector and activation materials (Au, Co, Ni, Al, Fe, and NaI). If the neutron field stability is proven, the radial channel beam can be used for evaluation of spectrum weighted cross section disregarding changes in the core configuration. Assuming reactions with higher threshold, their rates can be compared with rates obtained in the pure prompt fission neutron spectrum (PFNS), since earlier measurements have shown that the neutron spectrum in the light water reactor cavity is equal to the PFNS above 6 MeV threshold. Result 1.1831 mb for 127I(n,2n) reaction evaluated from the VR-1 activation measurement demonstrates good agreement of the measured reaction rate with tabulated rate averaged in 235U PFNS, confirming the neutron spectrum stability and equality to the PFNS.

Design optimization of the satellite in precessional transmission

One of the important tasks in the design of gears and gearboxes based on them is to increase the load capacity, durability and noise reduction with moderate requirements for manufacturing precision by providing elastic compliance of the teeth with simple satellite manufacturing technology. In the paper is firstly presented a base satellite in a precessional transmission. The design is rigid and non-technological. There was simulated the workload and the results are presented as a linear deformation. Simulation was based on the special module for the calculation and analysis of complex structures using the integrated module Stress Analysis (program Autodesk Inventor Professional 2012). It uses the finite element method calculation, based on the ANSYS program. Then is shown an optimized satellite structure. This option provides an increased durability and noise reduction due to local and general tooth compliance. The main drawback of this satellite is the high laboriousness of making cut-outs in the satellite. In this satellite, by increasing the diameter of the radial channel, it is possible to reduce the wall thickness and thereby increase the compliance. The simulation results of a new satellite design are presented. Compliance increased roughly by 4 times compared to the base version. When the gear is in mesh with the satellite, due to the increased elastic compliance of the teeth, a multi-pairing mesh is achieved, which reduces the contact loads and noise, increases the service life of the transmission.