Papers by Keyword: Blade

Abstract: This paper describes QForm computer simulation of a large-sized blade preform shaping, using cross-wedge rolling. Scenarios of friction consideration between the workpiece and the tool are examined.

Abstract: In this paper, based on the theoretical study of tool wear and the systematic analysis of the main factors affecting the tool durability, four types of PVD and CVD-coated blades from three manufacturers were subjected to cutting tests using PCrNi3MoVA gun steel workpieces. The wear morphology, fatigue curves, and chip patterns of the tested blades were comparatively analyzed. The influence of the coating type on the tool durability was investigated using a scanning electron microscopy and energy dispersive spectroscopy. The results obtained strongly indicate that TiAlN coating deposited by the PVD technology has the best thermal stability, temperature oxidation resistance, and tool durability when cutting PCrNi3MoVA gun steel workpieces under semi-finishing conditions. The wear resistance of the other three types of blades was relatively lower due to less favorable coating compositions and structures. The study findings are instrumental in the substantiated selection of cutters for practical applications and provide a reference for the design optimization of indexable coated inserts.

Abstract: In this paper, based on the technical theory developed by the article contributors and the theory designed for twisting of a composite laminated rod of any cross section, a computer program for numerical stress-strain analysis of laminated composite blades in the centrifugal forces field is presented. The naturally twisted laminated composite blade is considered to be under the combined action of the tensile stresses, bending and twisting moments or under the influence of centrifugal forces. In the program, the technological problem of blade unfolding into petals is solved. These petals lie in planes which are parallel to the rod axis and appear due to the varying cross-section along the length of the blade. The investigated blade is represented with eight sections. The results of research on stress-strain behaviour of boron aluminium laminated compressor blades which operate in the fields of centrifugal forces are analysed.

Abstract: This paper presents results from modeling of Compressor Turbine (CT) blades for short-haul aircraft fleet occasioned by thermo-mechanical stresses in order to comprehend the occurrence of premature failure. A 3D PT6A-114A engine high pressure (HP) CT blade geometrical model was developed in commercial CAD-SolidWorks, then imported to ANSYS 15.0 environment for finite element analysis (FEA). The CT blade was investigated for transient thermal stresses from heat generated by the combustors and static structural stresses from rotational velocities of the engine which account for 80% of inertial field during flight. The results revealed that the blades could have served for another 1.44% of the time they were in service.

Abstract: This paper deals with a comparative study of the outlet pressure-energy between a conventional and normal blade impeller and an airfoil-shaped blade impeller of a centrifugal pump. Although the volute casing is an important component along with an impeller [1], the present comparative analysis makes the volute casing redundant to the study, hence neglected. All centrifugal pumps are usually designed and manufactured using backward swept blades with equal camber on the top and bottom sides. An increased camber on the top side is an ideal trait for a lift generating airfoil. The purpose is to implement the principle of lift generation of airfoil for centrifugal pumps. As a result, a local suction side and pressure side can be visualized using CFX-post processor. The 3D analysis of such a centrifugal pump impeller is designed in SOLIDWORKS® and analyzed using ANSYS® CFX. The SST (Menter’s Shear Stress Transport) model is used as it combines both the k-ω and k-ε turbulence models.

Abstract: The paper concerns with the numerical modeling of wet steam flow through a blade cascade in transonic regime with non-equilibrium condensation in 2D. Real thermodynamics of vapor phase is implemented in the way which mostly avoid iterations in order to calculate thermodynamic properties. This equation of state is represented by the function for non-dimensional entropy with independent variables scaled density and scaled internal energy. Other equations of state are used for comparison, namely special gas equation which comes from IAPWS-95 formulation and simple pseudo perfect gas relation. We applied simple homogeneous non-equilibrium approach to model two-phase flow. Laminar compressible Navier-Stokes system of equations is used for the mixture properties. Liquid phase is described by the standard method of moments of droplet number distribution function. We consider obtained numerical results to be in good agreement with the measured data. We note the fact that robust and accurate closure of supplementary liquid system (nucleation rate and droplet growth model) is still not available and most often ad-hoc corrections are proposed by the authors. Results show differences among used equations of state as well. This is apparent mainly in the vicinity of condensation shock region on the suction side.

Abstract: The cyclic load number of aero-engine blade during its service life is very likely beyond 107, which is regarded as the conventional fatigue limit. Moreover, surface strengthening is very often used in the manufacturing process of blade. The conventional testing method in the VHCF regime cannot exactly reflect the stress state of the blade, including the mechanism of crack initiation. To study the fatigue behavior and effects of laser shock peening, a kind of bending fatigue subcomponent specimen was designed and the laser shock peening model was established. Experiment about TC17 was accomplished by the Ulra-High Cycle bending fatigue system. It is found that the fatigue damage occurs beneath the surface and the S-N curve is continuously rather than multi-step declining in the VHCF regime. Process of surface strengthening has a significant effect on fatigue performance of TC17 titanium alloy.

Abstract: The Ram Air Turbine system is the emergency power system of aircraft. As the key parts, the blades aerodynamic characteristic effects the system properties. In this article, CFD numerical method will be used to research four blades properties of ram air turbine. We compare the blades work properties of each working condition, so that we can get which design is better. We used the CFD numerical method to design the RAT blade, we hope this method will be used in our future products design.

Abstract: The article provides main dynamic models formed in geokhod drive, as well as demonstrates their influence on cutting forces of blade actuator.

Abstract: The paper presents the investigations made on samples taken from the related rotor blade of an hospital cooling equipment.The failure analysis was made in order to find if the failure appear because the metallic material used or was functional problem.The objectives of our analysis and techniques used are described below:determining the chemical composition by optical emission spectrometry;determining the hardness of the material;metallographic analysis by optical microscopy;micro compositional and microstructural analysis by scanning electron microscopy (SEM) and by microanalysis, energy dispersive X-ray (EDAX). Research has highlighted the quality of piece elaboration and casting, which led to a long life of its use.