Frequency: Quarterly E- ISSN: 2277-6257 P- ISSN: 2349-350X Abstracted/ Indexed in: Ulrich's International Periodical Directory, Google Scholar, SCIRUS, Genamics JournalSeek, EBSCO Information Services
Quarterly published "Inventi Impact: Mechanical Engineering" focuses on the theory and practice aspects of process engineering, machine design, and manufacturing and maintenance of mechanical systems. Also included are the issues related to mechanics, kinematics, thermodynamics, material science, structural analysis and electricity.
Machining process simulation is a method to increase machining quality and efficiency. The right cutting tool geometry and parameters are chosen during the machining simulation process to create a variety of precision component shapes. A machining simulation for the production of polygonal shafts is presented in this paper. The quality of the parabolic shaft during manufacture will be directly impacted by the machining process, which is simulated using the proper tools and appropriate machining parameters. CAM ESPRIT TNG (x64) software is used in the simulation to simulate the turning and milling process. The machining process can be made more efficient because the simulation process demonstrates that every step of the process operates as intended....
The extensive use of the pump as a turbine (PAT) for micro-hydropower applications has a significant value from economic and technical viewpoints. However, the unavailability of the characteristics curve and relatively lower efficiency are the two basic limitations when considering pumps for power-generating applications. In this paper, the performance of the PAT is analyzed using the computational fluid dynamics (CFD) software called Ansys CFX in conjunction with standard k-ε. Then, experiments were done to verify the results of the simulation. Measurement inaccuracy effects are also taken into account. The initial performance of the PAT is refined by controlling basic design parameters (i.e., increasing the number of impeller blades, decreasing blade thickness, blade tip rounding, and adjusting blade inlet angle). Additionally, a new modification method known as blade grooving is also introduced in this research. Finally, all listed modification techniques are applied simultaneously to achieve maximum performance. The output of the study confirms that the adopted modification techniques have a positive effect on performance improvement. When the number of impellers is increased, the power output is enhanced by 5.72%, and blade grooving provides the most efficiency improvement, i.e., 7.00%. But decreasing blade thickness has no remarkable impact on the performance; the power output and efficiency are improved by 1.24% and 2.60%, respectively. The maximum performance improvement was achieved when the modification techniques are applied simultaneously with 10.56 and 10.20 percent of power and efficiency increments, respectively. From the entire study, it can be concluded that the chosen design parameters have an important effect on stabilizing the internal flow, decreasing the required head, decreasing the hydraulic loss in the impeller, and increasing the overall performance. The study also helps to figure out which modification technique is the most practical....
Condition-based monitoring (CBM) has advanced to the stage where industry is now demanding machinery that possesses\r\nself-diagnosis ability. This need has spurred the CBM research to be applicable in more expanded areas over the past decades.\r\nThere are two critical issues in implementing CBM in harsh environments using embedded systems: computational efficiency\r\nand adaptability. In this paper, a computationally efficient and adaptive approach including simple principal component analysis\r\n(SPCA) for feature dimensionality reduction and K-means clustering for classification is proposed for online embedded machinery\r\ndiagnosis. Compared with the standard principal component analysis (PCA) and kernel principal component analysis (KPCA),\r\nSPCA is adaptive in nature and has lower algorithm complexity when dealing with a large amount of data. The effectiveness of\r\nthe proposed approach is firstly validated using a standard rolling element bearing test dataset on a personal computer. It is then\r\ndeployed on an embedded real-time controller and used to monitor a rotating shaft. It was found that the proposed approach\r\nscaled well, whereas the standard PCA-based approach broke down when data quantity increased to a certain level. Furthermore,\r\nthe proposed approach achieved 90% accuracy when diagnosing an induced fault compared to 59% accuracy obtained using the\r\nstandard PCA-based approach....
Spur gears are widely used transmission components. In the traditional design process, the noninvolute part of the tooth profile\ncurve is difficult to describe with mathematical equations. This article puts forward a new parametric modeling method, which can\ndescribe the modified involute part of spur gears and parameterize and optimize the transition part of the involute curve of the\nspur gear. And this model of the spur gear can be created by parameters which is input in Scilab software and the spur gear graphic\ncan be completed correspondingly. The experiments show that this modeling method can more quickly produce the standard spur\nor modified spur gear, and it also improves the efficiency and accuracy of spur gear modeling....
This paper presents an improved method for inclusion of system rotation and streamline curvature effects into existing twoequation\r\neddy-viscosity turbulence models. A new formulation for calculation of the turbulence viscosity coefficient, which is\r\nimplemented into the traditional K-E model with a two-layer near-wall treatment in a commercial computational fluid dynamics\r\nsolver, is proposed. In contrast to precious model, the modi??ed rotation rate which appears in the formulation for turbulent viscosity\r\ncoefficient is herein expressed exactly and universally. Thus, it provides an effective alternative for turbulence modeling....
A novel systematic framework, infrared thermography- (IRT-) based method, for rotating machinery fault diagnosis under\nnonstationary running conditions is presented in this paper. In this framework, IRT technique is first applied to obtain the\nthermograph. Then, the fault features are extracted using bag-of-visual-word (BoVW) from the IRT images. In the end, support\nvector machine (SVM) is utilized to automatically identify the fault patterns of rotating machinery.The effectiveness of proposed\nmethod is evaluated using lab experimental signal of rotating machinery. The diagnosis results show that the IRT-based method\nhas certain advantages in classification rotating machinery faults under nonstationary running conditions compared with the\ntraditional vibration-based method....
Vibration signal, as an important means for diesel engine condition detection and fault diagnosis, has attracted attention for many\nyears. In traditional vibration signal analysis, most processing methods are for single-channel data. However, single-channel\nvibration signal cannot reflect the operating information of the diesel engine comprehensively because diesel engine vibration is\ncoupled by multiple source signals. This paper proposes the MVMD band energy method for fault diagnosis by four channels of\nvibration signals. First, the original multivariate signals are decomposed adaptively by MVMD, which obtains a series of\ncomponents with modal alignment. Then, the band energy values of each measuring point are calculated as the fault characteristics.\nFinally, SVM is used to realize the diagnosis and identification of diesel engine misfire. The working conditions have a\ngreat influence on the vibration signal of the cylinder. In order to obtain the best diagnostic working conditions, six working\nconditions are set for testing. The result shows that the fault identification rate is highest under the 1500 rpm and 50% load\nworking condition. The fault recognition rate of this method reaches more than 99%, which is superior to the other four\ncommon methods....
We present a numerical methodology for evaluating wave propagation phenomena in two dimensions in the time domain with focus on the linear acoustic second-order wave equation. An outline of the higher-order compact discretization schemes followed by the time discretization technique is first presented. The method is completed with the addition of spatial filtering based on the same compact schemes' principles. The important role of boundary conditions is subsequently addressed. Two popular ways to truncate the computational domain in the near field are presented and compared here: first the formulation of ââ?¬Å?absorbing conditionsââ?¬Â in the form of partial differential equations especially for the origin and second the construction of an absorbing layer surrounding the domain, in which waves (after they have exited the domain) are attenuated and decayed exponentially. Subsequently, the method is assessed by recalling three benchmark problems. In the first where a Gaussian pulse is generated and propagated in a 2D rectangular domain, the accuracy and absorbability of the boundary conditions are compared. In the second, a similar situation is investigated but under curvilinear coordinates and under the presence of a solid body which scatters the pulse. Finally the sound field inducted by the flow of corotating vortex pair is calculated and compared with the corresponding analytical solution....
This paper reviews technical and clinical impact of theMicrosoft Kinect in physical therapy and rehabilitation. It covers the studies\non patients with neurological disorders including stroke, Parkinson�s, cerebral palsy, and MS as well as the elderly patients. Search\nresults in Pubmed andGoogle scholar reveal increasing interest in usingKinect in medical application. Relevant papers are reviewed\nand divided into three groups: (1) papers which evaluated Kinect�s accuracy and reliability, (2) papers which used Kinect for a\nrehabilitation system and provided clinical evaluation involving patients, and (3) papers which proposed a Kinect-based system for\nrehabilitation but fell short of providing clinical validation. At last, to serve as technical comparison to help future rehabilitation\ndesign other sensors similar to Kinect are reviewed....
This paper reports the planning efforts and preliminary results of increasing fuel economy in the current fleet of medium-duty tactical truck. A strategic plan was developed through investigation of current and future technology offerings from original equipment manufacturers and after market suppliers. Research efforts consisted of an initial phase where a broad range of integration candidates were collected and a secondary phase where in-depth analysis was conducted to target those to be considered for inclusion in the strategic plan. The strategic plan lays out the integrated technologies in the near term including auxiliary electrification of engine cooling fan and hydrogen injection. For the mid-term time frame, the plan involves implementing an engine stop/start system and electrifying other auxiliaries. The final step in the plan is the development and implementation of a full hybrid population. The preliminary results include simulation of the electric cooling fan and mild hybrid powertrain, and experimental test of hydrogen injection....
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