- TITLE:
CALCULATING EVALUATION OF THERMAL EFFICIENCY OF THE SOLAR DRYING INSTALLATIONS WITH STRAIN SOLAR COLLECTORS
- AUTHOR(S):
Z.S. Iskandarov, K.T. Norkulova, B.M. Jumaev
- ABSTRACT:
In this paper the estimated efficiency of solar drying plants with in-line solar collectors is given. The dependence of the
thermal efficiency of solar drying plants with solar collectors is determined. It is possible to optimize the temperature of the essential agent
at the outlet of the solar collector.
- TITLE:
TORSIONAL VIBRATIONS OF A SHAFT CAUSED BY IMPRECISIONS IN THE TRANSMISSION
- AUTHOR(S):
S. Pulev, G. Tonkova
- ABSTRACT:
This work investigates the influence of a possible defect in electric motors - eccentricity in the transmission between the rotating shaft
and the motor. Kinematic disturbance is used to describe the imprecision. A mechano-mathematical model with two degrees of freedom is
used. The differential equations describing the vibrations are derived with methods from analytical mechanics. The law of the torsional
vibrations is derived analytically. Values are obtained for the periodically changing dynamic twisting moments of the shaft's sections. A
numerical example is provided along with diagrams and amplitude-frequency response charts of the vibrations.
- TITLE:
ON THE APPLICATION OF THE FUNCTIONAL APPROACH TO THE METHODS OF PROCESSING LAYERED SUPERHARD COMPOSITES
- AUTHOR(S):
E. Lashko, O. Salenko, V. Shchetynin, S. Klimenko, S. Melnichuk
- ABSTRACT:
Layered superhard composites are widely used in the manufacture of tool components, special products of aviation and space technology.
Typically, these products are a plates of regular geometric shape, the final shaping of which is made by diamond grinding. Proposed finish
processing of composite materials is to implement hybrid methods based on laser-jet technologies, with use the functional approach. In
terms of composite materials processing laser-jet is a hybrid, capable of a certain way to influence the components of the composite at
different levels – from nanozone to macrovolume. The hybridization process, which is consist of scribing, water-jet cutting, smoothing of the
surface will allow according to the structure of the processed composite plates get high quality cuts. Field experiments were performed on
laser-jet complex of LSK-400-5, equipped with a abrasive-jet head with water nozzle d c=0,22 mm and calibration tube Dk=1,05 mm, and
also a system of combining a laser jet with the liquid stream by means of flying optics. Process of cutting the plates was performed using a
Nd: YAG laser with a power of 400 W, and operating at a frequency of 50 Hz. Composite plate is a layered system coated with base layer of
cubic boron nitride with 2,8 mm, common plate thickness – 4,5 mm. Using a functional approach allowed us to obtain high-quality cut (the
roughness of the end is 3,2 μm, the width of the slot is 0,12 mm), while the time to perform the operation of cutting at a specified contour
made up only 1,8 min.
- TITLE:
3D MODELING OF CUTTING-DEFORMING TAPS
- AUTHOR(S):
M. Nikolova- Pencheva, I. Alexandrova, J. Mitev
- ABSTRACT:
The paper presents the methodology and the algorithm for a construction of a 3D model of cutting-deforming taps with new design,
forming the threads by combining cutting and plastic deformation methods. Formulas for calculation of the structural elements of the
cutting-deforming taps have been presented using the threads parameters as input data for tools design. Autodesk Inventor system has been
used. The stages of the 3D model construction have been presented. The created 3D model is a basis for a strengt h-strain study of cutting-
deforming taps and for a generation of a program for the production of CNC machines using CAM module.
- TITLE:
A DESIGN METHODOLOGY FOR A BIDIRECTIONAL SERIES RESONANT DC-DC CONVERTER
- AUTHOR(S):
A.S. Vuchev, A. A. Lichev, P. N. Georgiev
- ABSTRACT:
Results from an approximate analysis of a bidirectional series resonant DC-DC converter
operating above the resonant frequency are discussed. The converter control technique is taken into
consideration. A methodology for design of the converter is proposed. Calculations for a 200W
converter are made. The obtained results are verified by simulation investigations.
