PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING最新文献_第8页

Identification of Turbomachinery Noise Sources via Processing Beamforming Data Using Principal Component Analysis 利用主成分分析处理波束形成数据识别涡轮机械噪声源

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-12-14 DOI: 10.3311/ppme.18555

B. Fenyvesi, Csaba Horváth

{"title":"Identification of Turbomachinery Noise Sources via Processing Beamforming Data Using Principal Component Analysis","authors":"B. Fenyvesi, Csaba Horváth","doi":"10.3311/ppme.18555","DOIUrl":"https://doi.org/10.3311/ppme.18555","url":null,"abstract":"Complex turbomachinery systems produce a wide range of noise components. The goal is to identify noise source categories, determine their characteristic noise patterns and locations. Researchers can then use this information to quantify the impact of these noise sources, based on which new design guidelines can be proposed. Phased array microphone measurements processed with acoustic beamforming technology provide noise source maps for pre-determined frequency bands (i.e., bins) of the investigated spectrum. However, multiple noise generation mechanisms can be active in any given frequency bin. Therefore, the identification of individual noise sources is difficult and time consuming when using conventional methods, such as manual sorting. This study presents a method for combining beamforming with Principal Component Analysis (PCA) methods in order to identify and separate apart turbomachinery noise sources with strong harmonics. The method is presented through the investigation of Counter-Rotating Open Rotor (CROR) noise sources. It has been found that the proposed semi-automatic method was able to extract even weak noise source patterns that repeat throughout the data set of the beamforming maps. The analysis yields results that are easy to comprehend without special prior knowledge and is an effective tool for identifying and localizing noise sources for the acoustic investigation of various turbomachinery applications.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":"12 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84199717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Testing of a Radiant Wall Cooling System with Pipes Coupled to Aerated Blocks 管道耦合加气块辐射壁冷却系统的试验研究

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-12-09 DOI: 10.3311/ppme.18734

M. Simko, D. Petráš, M. Krajčík, D. Szabó

{"title":"Testing of a Radiant Wall Cooling System with Pipes Coupled to Aerated Blocks","authors":"M. Simko, D. Petráš, M. Krajčík, D. Szabó","doi":"10.3311/ppme.18734","DOIUrl":"https://doi.org/10.3311/ppme.18734","url":null,"abstract":"Thermal output, surface temperatures, and supply and return water temperature were measured for a wall cooling system involving pipe attached to a wall section made of thermally insulating blocks. The experiment was performed for warm climatic conditions typical of, e.g., summer in Central and Northern Europe. The outdoor environment was simulated by a climatic chamber while the indoor climate was simulated by attaching a hotbox to the wall surface. The sensitivity of thermal output to several design parameters was investigated by 2D numerical simulations. The measurements showed a fast thermal response of the wall system. The cooling output was 38.3 W per m2 of the cooling area which equalled about 4.8 W/m2 per 1 K temperature difference between water and hotbox. The lowest surface temperature of 19.6 °C was measured at the pipe. Thus, the cooling output could be enhanced by reducing the surface temperature closer to the dew point temperature. The temperature of water in the pipe was very close to the surface temperature. It was illustrated how this characteristic of the wall cooling system tested positively affects the efficiency and cooling capacity of an air-to-water heat pump.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":"93 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80828202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Investigation of the Tubular and Cylindrical Billets Stamping by Rolling Process with the Use of Computer Simulation 用计算机模拟技术研究管、圆柱坯的滚压成形工艺

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-12-08 DOI: 10.3311/ppme.18659

Viktor Matvijchuk, A. Shtuts, M. Kolisnyk, I. Kupchuk, I. Derevenko

{"title":"Investigation of the Tubular and Cylindrical Billets Stamping by Rolling Process with the Use of Computer Simulation","authors":"Viktor Matvijchuk, A. Shtuts, M. Kolisnyk, I. Kupchuk, I. Derevenko","doi":"10.3311/ppme.18659","DOIUrl":"https://doi.org/10.3311/ppme.18659","url":null,"abstract":"Forming of blanks during stamping by rolling (RS) is possible according to technological schemes of deposition, landing, direct and reverse extrusion, distribution and compression, etc. Controlling the relative position and shape of the deformed tool allows you to control the direction of flow of the workpiece material and the nature of its formation, as well as the stress-strain state of the material. The complexity and versatility of RS processes necessitate computer modeling for sound management of basic technological parameters.Physical experimental as well as computer modeling of the RS process in the DEFORM-3D software package was performed in the work.According to the results of computer simulation, the distribution of deformation components, stresses and temperatures in the deformed workpiece area was obtained, and using the Cockroft-Latham criterion, the destruction of metals during cold deformation was also predicted.Physical modeling of the SR process on lead blanks confirmed the nature of their deformation, obtained by computer simulation. And the analysis of the stress-strain state of the material based on the results of measurements of the deformed grid confirmed the validity of the appointment of boundary conditions in computer simulation.This approach is suitable for modeling by the method of SR of any metal models, for which it is necessary to know their mechanical characteristics, including boundary deformation curves.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":"164 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88453778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Investigation of the Required Discreteness of Interpolation Movement Parameters in Cyber-physical Systems 网络物理系统中插值运动参数所需离散性的研究

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-12-06 DOI: 10.3311/ppme.17884

V. Kombarov, Yevgen Tsegelnyk, Sergiy Plankovskyy, Ye. Aksonov, Ye. Kryzhyvets

引用次数: 2

Fracture Mechanical Analysis of Gleeble Simulated Heat Affected Zones in High Strength Steels 高强度钢Gleeble模拟热影响区的断裂力学分析

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-12-01 DOI: 10.3311/ppme.19077

Z. Koncsik, J. Lukács, G. Nagy

引用次数: 0

Modeling Analysis and Simulation of Wheel Suspension System's Response for Quarter Car Model by Using 20-sim Software for Honda Civic Lx 2019 Sedan 基于20-sim软件的本田思域Lx 2019轿车四分之一车型车轮悬架系统响应建模分析与仿真

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-11-17 DOI: 10.3311/ppme.18239

H. H. Hadwan, M. A. Mahdi, Ahmed W Hussein

引用次数: 0

The Effect of Processing Parameters and Calcium-stearate on the Ejection Process of Injection Molded Poly(Lactic Acid) Products 工艺参数及硬脂酸钙对聚乳酸注塑成型产品挤出过程的影响

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-10-25 DOI: 10.3311/ppme.18246

T. Tábi, K. Pölöskei

{"title":"The Effect of Processing Parameters and Calcium-stearate on the Ejection Process of Injection Molded Poly(Lactic Acid) Products","authors":"T. Tábi, K. Pölöskei","doi":"10.3311/ppme.18246","DOIUrl":"https://doi.org/10.3311/ppme.18246","url":null,"abstract":"We investigated the ejection/demolding of continuous production of injection molded Poly(Lactic Acid) tensile testing specimens and analyzed the effect of 1 wt% Calcium-Stearate additive as demolding agent (sliding or mold release agent) on this process. We demonstrated that the Poly(Lactic Acid) specimens could get stuck in the mold or even break during demolding during continuous injection molding in a certain type of mold, which has a low draft angle and varying cavity width along the flow path. The standard dumbbell-shaped tensile testing specimen is produced in such a mold. Demolding was rated with the use of a high-speed camera into three categories (problem-free demolding / stuck, but demolded undamaged product / stuck and damaged product). Moreover, the ejector force required to push the product out of the cavity was monitored over 30 continuous injection molding cycles. We also investigated the effect of processing parameters, such as injection rate (screw speed), holding pressure, holding time, mold temperature, melt temperature, backpressure, screw rotational speed, and pre-process drying (drying or not drying the pellets before injection molding). We managed to avoid product breakage during demolding with the proper settings of certain process parameters and the use of Calcium-Stearate, an effective demolding agent. This ensured problem-free demolding and thus continuous injection molding.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":"318 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72987037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

An Experimental Study on the Force Coefficient and the Discharge Coefficient of a Safety Valve in Air-water Mixture Flow 气-水混合流中安全阀力系数和流量系数的实验研究

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-09-24 DOI: 10.3311/ppme.17848

Mhd Ghaith Burhani, C. Hős

{"title":"An Experimental Study on the Force Coefficient and the Discharge Coefficient of a Safety Valve in Air-water Mixture Flow","authors":"Mhd Ghaith Burhani, C. Hős","doi":"10.3311/ppme.17848","DOIUrl":"https://doi.org/10.3311/ppme.17848","url":null,"abstract":"Due to the low number of experimental investigations on the sizing of safety valves in multiphase flow, a novel set of measurement data of an air-water mixture is reported. This paper presents an experimental study on three different geometries of safety valves, a poppet valve with jet angle θ = 120°, and two-disc valves with deflection angles θ = 0° and θ = 90°, respectively. Our test rig comprises a pipeline with 42.5 mm inner diameter, spray nozzles to supply the added water quality (water mass fraction) to the pressurized airflow up to 40 % mass fraction and an inlet pressure up to 6.6 bar(g). The time histories of force, valve lift, and pressures were recorded. We present correlation data for the force coefficient and the discharge coefficient. The widely used omega technique for the Homogenous Equilibrium Model (HEM) is employed to predict the theoretical mass flux. The results show that the poppet valve experiences less momentum force and lower mass flow rates compared to disc valves, while the disc valve with deflection angle θ = 90° presents the highest discharged flow rates among the tested geometries. Our most important finding is that up to 60 % relative valve lift and 40 % mass fraction, neither the force nor the discharge coefficient changes significantly compared to the pure-air case. Finally, we propose a new correlation with a single equation for the resultant force and the discharge coefficient as a function of the relative valve lift for all tested water mass fractions.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":"58 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84740725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Comparative Analysis of Heat Pump System with IHX Using R1234yf and R134a 采用R1234yf和R134a的IHX热泵系统对比分析

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-09-24 DOI: 10.3311/ppme.18390

R. Sánta

引用次数: 2

Decomposition of Velocity Field Along a Centerline Curve Using Frenet-Frames: Application to Arterial Blood Flow Simulations 利用frenet框架沿中心线曲线分解速度场:在动脉血流模拟中的应用

IF 1.3

PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING Pub Date : 2021-09-24 DOI: 10.3311/ppme.18517

B. Csippa, Levente Sándor, G. Paál

{"title":"Decomposition of Velocity Field Along a Centerline Curve Using Frenet-Frames: Application to Arterial Blood Flow Simulations","authors":"B. Csippa, Levente Sándor, G. Paál","doi":"10.3311/ppme.18517","DOIUrl":"https://doi.org/10.3311/ppme.18517","url":null,"abstract":"This paper presents a novel method for the evaluation of three-dimensional blood-flow simulations based, on the decomposition of the velocity field into localized coordinate systems along the vessels centerline. The method is based on the computation of accurate centerlines with the Vascular Modeling Toolkit (VMTK) library, to calculate the localized Frenet-frames along the centerline and the morphological features, namely the curvature and torsion. Using the Frenet-frame unit vectors, the velocity field can be decomposed into axial, circumferential and radial components and visualized in a diagram along the centerline. This paper includes case studies with four idealized geometries resembling the carotid siphon and two patient-specific cases to demonstrate the capability of the method and the connection between morphology and flow. The proposed evaluation method presented in this paper can be easily extended to other derived quantities of the velocity fields, such as the wall shear stress field. Furthermore, it can be used in other fields of engineering with tubular cross-sections with complex torsion and curvature distribution.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":"62 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84976170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1