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An analysis is made of the technology of vortex cutting method of groove for sealing rings provided on the lateral surfaces of rotation of a part of the sealing system and the dimensional chains thus formed, as well as accuracy issues by applying probability theories and dimensional chains. Features of the developed technology are presented; the factors influencing the accuracy of the circular diameter...
Wire electrical discharge turning (WEDT) is a non-conventional machining process, which was developed to machine cylindrical components on difficult-to-machine, but electrically conductive materials with high precision. In the present work, roundness, cylindricity and areal surface roughness of the parts created by WEDT process are investigated. Inconel 825 was the material chosen for the present...
Surface modification of a lubricated bearing, such as hydrophobic coating inducing slip situation and texturing, is proved to enhance hydrodynamic performance. As widely known, in textured surface lubricant inertia and cavitation can significantly affect the hydrodynamic pressure profile. However, a brief literature review indicates that studies related to the correlation between cavitation and inertia,...
High-pressure water jet technology is a clean and effective approach to break, cut or clean solid materials. The nozzle’s hydraulic performance determines the efficiency and quality of the high-pressure water jet technology implementation. The fluid resistance reduction technology of bionic non-smooth surface is applied to the structural design of the straight cone nozzle successfully. The circular...
This paper presents a numerical study on waste heat recovery from a fluid stream using thermoelectric elements for energy harvesting. Two fluids were tested, air and steam, and the voltage and overall efficiency were computed for different sets of operational conditions. The mathematical description considered turbulent regime and coupled transport phenomena for the description of the main thermoelectric...
Recently, polymer composite materials are the most widely used elements in engineering applications. In this work, hybrid polymer composites of epoxy (E) reinforced with sisal (SF), banana (BF), coir (CF) and sisal/banana/coir (SBCF) fibers were fabricated by compression molding process. Five different kinds of laminates were prepared in the following stacking sequence of E, E/SF, E/BF, E/CF and E/SBCF...
As an important period of self-priming process, the startup process of self-priming pump is inevitable. In this paper, a small overhung self-priming centrifugal pump is tested to reveal the effect of startup time on startup performance. As a first step, the startup performance of the pump delivering water is tried firstly. Through testing, the transient characteristics of performance variables against...
The purpose of this study is to investigate the impacts of diesel–biodiesel–alcohol blends on the combustion, performance and emissions characteristics of a single-cylinder diesel engine. Tests were conducted at different engine speeds of 1750, 2250, 2750 and 3250 rpm and under full load. In this study, different fuels [called as reference diesel (D100), 20 vol% cottonseed methyl ester (D80C20), 10 vol%...
An air distributor is regarded as a key component of swirling fluidized bed designs. It considerably affects the quality of fluidization and efficiency of a swirling fluidized bed (SFB). In this study, a velocimetry technique was used to evaluate the performance of the SFB design operated with a mesh-coupled annular blade air distributor. The MATLAB-based particle image velocimetry (PIV) was carried...
Latent heat thermal energy storage (LHTES) plays a main role in many industrial applications, especially in high-powered electronics cooling systems and providing the thermal energy demand when the energy supply is unavailable. In this study, the LHTES cycle process, including successive melting and solidification, investigates in a two-dimensional annular space of a square cavity filled with nanomaterial...
Ratcheting and Bauschinger effect usually occur in the structures which are subjected to cyclic loading. It is necessary to research on the evolution rules of ratcheting and Bauschinger effect changed with cycle numbers and further to look into the influence on material mechanics property. In this work, asymmetrical stress-controlled cyclic loading tests on Q235 steel have been conducted to obtain...
Today, there are many commercial CAM systems available capable of generating NC codes for milling free-form geometries up to 5-axis. However, the quality of these NC codes has not yet been well discussed so far. Apparently, on the computer screen and the geometrical simulation provided by CAM, tool paths calculated by different CAM systems seem to be the same. However, as observed in this work, NC...
Titanium is predominantly used in the industrial sectors such as bio-medical, chemical, aircraft and marine because of its improved properties such as corrosion resistance and strength. Other properties such as increased toughness, hardness, poor thermal diffusivity make the material to fall under the category of difficult-to-cut, and this gave rise to the introduction of advanced machining processes...
Humidifiers are the important devices for humidifying the air both in life and industrial production. This paper focuses on the heat and mass transfer processes inside the counter-flow packing humidifier at atmospheric pressure. Based on mass and energy balance, the mathematical model for the humidifier is established. The finite difference method is first adopted to calculate the specific scales...
The need for larger and more efficient structures has led to the development of numerical models to approach real-world complex behaviors. Normally, engineering systems consider deterministic parameters, while in real-world situations, they are subjected to parametric uncertainties, resulting in differences between the calculated responses. This work is devoted to performing numerical and computational...
Engineering applications for precision cylindrical parts have required increasingly tight geometric tolerances to guarantee their correct functionality. In addition to demanding better machine tools and manufacturing processes, it is also important to have the means to verify if the qualities of precision cylindrical components meet the requirements. Optical measurement techniques are excellent options...
The hybrid manipulators have benefits of both serial as well as parallel manipulators. In this paper, a planar hybrid manipulator with six degrees-of-freedom is proposed; it consists of two parallel manipulators each having three degrees-of-freedom. The models for forward and inverse dynamic analysis of this manipulator are presented with bond graph approach. The actuators of the manipulator have...
Titanium (Ti)-based alloy is extensively used in the biomedical field due to its properties that promote osseointegration. The present work deals with an experimental study on the effect of microcutting of Ti–6Al–7Nb on corrosion resistance and surface characteristics for enhanced biocompatibility. Experiments were carried out by using Taguchi L9 orthogonal array with process variables include cutting...
Based on the RNG k–ɛ turbulence model, the multi-coordinate system is used to simulate the three-dimensional unsteady constant value of the nuclear main pump model under different axial and circumferential positions of the guide vane and the annular casing. By analyzing the external characteristics, pressure field and velocity field of different schemes and comparing the pressure pulsation at the...
Ultra-precision cutting (UPC) technology can directly achieve freeform surfaces with form accuracy in sub-micrometer and surface finishing in nanometer, and the achieved surface quality affects the functionalities of the components. Different from the conventional machining process, the effects of workpiece material properties on surface generation in UPC are ignorable. The influences of plastic side...
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