Radial Wheels Research Articles

Numerical Study of the Strength Radial Turbomachines Based on the Use of Stainless Steel 316L

By studying various properties of materials came to the conclusion that stainless steel 316L has good properties. This material is suitable for making radial wheel turbines compared to other materials. The object of the study is a radial wheel with 10 blades manufactured by “Schiele” (Germany), which specializes in the production of units for the chemical industry and ventilation equipment. The finite element method was chosen as the basic research method for solving problems of natural and forced vibrations, static stress and studying the degree of reactivity blades radial wheels of turbomachines. It can be argued that the numerical analysis of the strength characteristics of heavily loaded turbine elements with the help of electronic computers provides a greater depth of research, the breadth of the issues covered, significantly reduces the amount of expensive experimental research, reduces the time for designing new turbines in terms of efficiency, reliability, technology and resource saving of highly loaded units. In this paper, calculations were made of the characteristics of natural frequencies, equivalent stresses, deformation and the degree of reactivity blades when using material stainless steel 316L. It is noted that this material provides the criterion of stress concentration in the wheel as low as possible and the natural frequencies of the wheel are reduced, but it does not lead to a change in the oscillation modes of this wheel. So 316L stainless steel is recommended for evaluating options in the manufacture of this radial wheel of turbomachines in the field of power, chemical and transport engineering.

Numerical Analysis for Optimization of the Lifetime Characteristics of Radial Wheels Turbomachines by Introducing the Intentional Mistuning Parameters

Numerical Analysis for Optimization of the Lifetime Characteristics of Radial Wheels Turbomachines by Introducing the Intentional Mistuning Parameters

Energy performance of farm tractor with single radial versus dual diagonal wheels in harrowing operations

ABSTRACT The farm tractor wheel interacts directly with the soil, affecting its energy and operational performance. Several works study the particularities between configurations of wheelset seeking to interpret the most efficient type and arrangement of the wheelset. However, there is still a demand for studies that elucidate decision-making regarding changing the type of wheelset or improving the pre-existing arrangement. The experiment aimed to evaluate the energy performance of farm tractors equipped with Single radial and Dual diagonal wheels in rear axle in intermediate harrowing operation. The experiment was conducted in a randomized block design. Two-wheel arrangements (Single radial and Dual diagonal) were used in the blocks, and four target velocities (4, 6, 8, and 10 km h-1), with four replicates in the subblocks, totalizing 32 experimental units. Slip of wheels, engine rotation, hourly and specific fuel consumption, force, power, and efficiency in the drawbar, operational velocity, and engine thermal efficiency were monitored. The data collected were submitted to analysis of variance and, when significant, to the Tukey test and regression analysis. The Single radial tires provided an increase in velocity and drawbar force without increasing fuel consumption, consequently providing an increase in energy and operating performance in intermediate harrowing operation.

МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ И ЧИСЛЕННАЯ ОЦЕНКА ДОЛГОВЕЧНОСТИ РАДИАЛЬНЫХ РАБОЧИХ КОЛЕС ТУРБОМАШИН

The radial blade discs are nominally designed to be cyclically symmetrical. But the vibration characteristics of all the ra-dial blades on the disc are slightly different due to manufacturing tolerances, variations in material properties and wear during operation. These small changes break the cyclic symmetry, break the pairs of eigenvalues and affect the durability of the radial impellers of turbomachines. In further work, the designs of such systems may fail before the estimated resource or service life. Therefore, when designing, manufacturing, and operating turbomachines, it is necessary to understand the effect of parameter mistuning to manage the resource and ensure the required level of strength, reliability, and durability of radial turbomachines. This study proposes a technique for mathematical modeling and prediction of high-cycle fatigue life of radial wheels tur-bines, taking into account dynamic loading. Numerical assessment of durability was performed on the example of a radial wheel with 10 blades manufactured by Schiele (Germany). The results were obtained when calculating the dynamic load in the MATLAB program and high-cycle fatigue in the ANSYS program.

On the long-term aging of S-phase in aluminum alloy 2618A

The aluminum alloy 2618A is applied for engine components such as radial compressor wheels which operate for long time at elevated temperatures. This results in coarsening of the hardening precipitates and degradation in mechanical properties during the long-term operation, which is not taken into account in the current lifetime prediction models due to the lack of quantitative microstructural and mechanical data. To address this issue, a quantitative investigation on the evolution of precipitates during long-term aging at 190 °C for up to 25,000 h was conducted. Detailed transmission electron microscopy (TEM) was combined with Brinell hardness measurements and thorough differential scanning calorimetry (DSC) experiments. The results show that GPB zones and S-phase Al2CuMg grow up to < 1,000 h during which the GPB zones dissolve and S-phase precipitates form. For longer aging times, only S-phase precipitates coarsen, which can be well described using the Lifshitz–Slyozov–Wagner theory of ripening. A thorough understanding of the underlying microstructural processes is a prerequisite to enable the integration of aging behavior into the established lifetime models for components manufactured from alloy 2618A.

The combined finishing of geometrically-complex parts

The paper describes the combined hydroabrasive dimensional processing, which involves the application of an electric field of metal parts with complex volumetric profiles, requiring jet control with reference to 5-6 coordinates. One should also consider the reciprocal impact of technological parameters upon formation of parts machined. The mechanism of dimensional material removal has been developed, which is the basis for working out the informational technology of a combined process. The objects of study are adjoining parts of spatially complex surfaces, like gas-turbine engine blades, or axial and radial wheels of turbopump units, as well as the processes of unsoldering in cooled parts of combustion chambers, jet nozzles and complex-shaped part sections with limited tool access into the processing zone, including those made from materials of low machinability. The combined process of hydroabrasive finishing has been developed, which involves the induction of electric current for geometrically-complex surfaces of any geometry, including in areas, inaccessible or hardly accessible for a metal-cutting tool when manufacturing parts from alloys of low machinability.

Centrifugal blood pumps--a brief analysis: development of new designs.

Analysis of 350 different sources of information from leading countries of the world enabled us to determine the availability of 20 different designs of centrifugal and rotary blood pumps. Most of them are for extracorporeal applications with radial pumping wheels of disc or vane type. The prospect of improving these designs was suggested by a combination of these two types. Five new designs based on the Biomedicus have been produced. Basic calculations are given for one of these with respect to limitations for shear stresses. It is proposed that the suggested designs will allow reductions in thrombosis and haemolysis which are the main problems for these pump designs.

Gravity as an orientation guide during web-construction in the orb spiderAraneus diadematus (Araneae, Araneidae)

The effect of gravity on the web building behaviour of the common garden spiderAraneus diadematus was studied in three ways: (i) frames with partially completed vertical webs were swivelled into a horizontal position, (ii) by rotating frames with spiders in a vertical klinostat (1 rpm), and (iii) by vertically rotating a partially completed web treadmill fashion keeping the building animal in a certain position in space. (i) In the horizontal, radial wheels are not constructed, however, a more or less irregular spiral is added to a completed wheel; (ii) in the klinostat the radial wheel lacks the up/down distinction of normal webs, and the spiral is irregular; (iii) in the treadmill the spiral course is abnormal, and the degree of deviation depends on the position of the animal. If the body axis is parallel to gravity the spiral path deviates to both sides of the norm. In ag perpendicular body position the path deviates predominantly to one side, spiralling sharply inwards towards the hub. The observations suggest that the cyclic changes in the body position of spiral-buildingAraneus are an important component of the animal's orientation during this phase of web-construction.

Reply to the objections of “M.” (Published in the October Number, page 260,) to a comparison between the radial and perpendicular paddle wheels for steamers

Reply to the objections of “M.” (Published in the October Number, page 260,) to a comparison between the radial and perpendicular paddle wheels for steamers

Remarks on radial and vertical paddle wheels

Remarks on radial and vertical paddle wheels

Investigation of the comparative merits of the perpendicular and radial paddle wheels for sea-going vessels

Investigation of the comparative merits of the perpendicular and radial paddle wheels for sea-going vessels

Investigation of the comparative merits of the perpendicular and radial paddle wheels for sea-going vessels

Investigation of the comparative merits of the perpendicular and radial paddle wheels for sea-going vessels