On the Analysis of Experimental Data for External Gear Machines and Their Comparison With Simulation Results

Author(s):  
Andrea Vacca ◽  
Germano Franzoni ◽  
Paolo Casoli

This paper deals with the simulation of hydraulic gear machines, focusing on the validation of simulation models and on the comparison between numerical results and experimental data, concerning both steady and unsteady conditions. First authors give a brief overview on the simulation tool HYGESim, which has been presented and discussed in several previous papers. Afterwards, the attention shifts on the analysis of the simulation results for the case of a stock gear pump. Regarding steady state characteristics, the paper shows how HYGESim is able to accurately reproduce the operation of the analyzed pump, in terms of flow, pressures and efficiency maps. Regarding unsteady simulations, namely the delivery pressure ripple, the paper highlights the significant effort done by the authors in order to achieve experimental data clear and suitable for the comparison with simulation results. In fact, the peculiarities of common measuring systems (in particular of the load apparatus and the sampling methods) are often difficult to reproduce numerically: frequently different acceptable assumptions in the numerical model lead to remarkable discrepancies in simulated results. For this purpose, the authors developed a measuring device mainly focused on the easy reproducibility in the simulation environment. Furthermore, an original technique for processing unsteady data (pressure and flow ripples) is proposed, allowing to achieve comparable data indifferently of the adopted sampling method and of the data origin (experimental or numerical). In the final part of the paper, pressure ripple simulations and test results (obtained with the described measuring system and analyzed with the described technique) are presented and compared.

2013 ◽  
Vol 744 ◽  
pp. 23-26
Author(s):  
Fan He Meng ◽  
Jun Hua Zhang

For the limitations of the existing hydraulic test bench for experimenting with multi-species of hydraulic components, the additional cartridge valve circuit and multi-way directional valve circuit were designed. The AMESim simulation models of the hydraulic test benchs basic hydraulic circuits were established and simulated. Then the simulation results were compared with the experimental data to get some principles of simulation modeling and optimize the models. These principles were used to simulate the additional hydraulic circuits. Through analysis of the simulation results, theory supports were provided to the optimal design of hydraulic test bench. In this way, the existing hydraulic test bench can be fully used and the suitable components were selected, reducing the waste of resources. Besides, the simulation models can be used as part of the virtual hydraulic teaching.


Author(s):  
Rohollah Abdollahi

In this paper, a novel delta/tapped star transformer for 36-pulse AC-DC converter configuration is designed, modeled, simulated and developed to feed isolated DC varying loads. The proposed AC-DC converter is suitable for large current rating rectifiers such as electrowinning, electrochemical processes, induction heating, etc. Its main feature is its reduced kilovolt-ampere (kVA) rating. The circuit has been designed for retrofit applications, a delta/tapped star-connected transformer platform is also included in the converter. First, we have simulated the proposed scheme via Matlab/Simulink software supplying different load conditions. Then, it has been implemented based on the motivation we have gained throughout the simulation results. The results show significant improvement in power quality indices (according to the IEEE-519) at the point of connection to the utility. We achieve less than 4% of input current total harmonic distortion (THD) with our proposed configuration for supplying different load scenarios. Moreover, we achieve a satisfying power factor (almost unity) for DTCIMD operation. Also, a prototype of the proposed transformer-based 36-pulse ac–dc converter has been developed, and test results are presented to validate the developed design procedure and the simulation models of this ac–dc converter.


Author(s):  
Kazuma Hirosaka ◽  
Hidekazu Takazawa ◽  
Katsumasa Miyazaki ◽  
Norihide Tohyama ◽  
Hiroyuki Nouji ◽  
...  

Aircraft impact analysis is needed for a safety assessment of nuclear power plants. One of the contents which should be analysed for aircraft impact is physical damage of a concrete building and this can be estimated by a numerical simulation. In order to conduct aircraft impact analysis, simulation model which validated by some experimental data needs to be established. In 1990s, impact test using actual F4 Phantom fighter was conducted at Sandia national laboratory in U.S. and a lot of important experimental data were measured. In this paper, the numerical simulation results for this F4 Phantom impact test are introduced. The relationship between the thickness of the shell of the F4 Phantom simulation model and the deceleration of this model is indicated and the differences of the deceleration between simulation and test results are discussed. In addition, the relationship between fracture strain of the shell of the F4 Phantom simulation model and the destruction mode of this model in simulation is indicated and the differences between the destruction mode of the F4 Phantom between simulation and test results are discussed. In order to evaluate the physical damage area after the aircraft impact, it is necessary to estimate the aircraft velocity after it perforates the outer concrete wall and to calculate the decrease of the kinematic energy of the aircraft by this perforation. In this paper, several aircraft impact simulations with different concrete wall thickness are conducted and the reduction in kinematic energies of an aircraft by a perforation is estimated. Using these simulation results, the necessary numbers of concrete walls until the impacting aircraft stops is discussed.


2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Hong Nhung Luu Thi ◽  
Trinh Nguyen Nhat ◽  
Linh Nguyen Thi Dieu ◽  
Le Nguyen Thi

Introduction: This paper is the result of the research “Development of bra pressure measuring system using air pressure sensor” developed in the Ha Noi University of Science and Technology in 2019.  Proplem: The pressure of the bra on the human body affects the comfort of the wearer and the wearer's health. Therefore, bra pressure is one of the most important parameters taken into account when designing and manufacturing bras. Objective: To determine the pressure value of a bra, it is necessary to use a suitable pressure measuring device. Methodology: The device operates on the principle of resitive gas pressure sensor, with 8 measuring channels. The system is controlled by the computer via programming software in the Visual C language, measuring the pressure of the shirt on the position on the curved surface of the human body. Pressure values ​​and timed charts are displayed on the computer. The measuring device was tested with GE Druck DPI 610 pressure generator.  Results: Test results showed that the device has a sensitivity of 0.01 kPa, measuring range from 0.1to 10 kPa and an accuracy of 0.01 kPa. Conclusion: This measurement system is important for objectively assessing the pressure of the bra on the wearer.  Originality: This paper presents the results of research and design of the PB228 system when measuring the pressure of the bra on the wearer's body in static, dynamic and static-dynamic combined states.  Limitations: The accuracy of the device only applies in standard conditions


Author(s):  
Aleksey Malahanov

A variant of the implementation of the behavioral model of a linear voltage stabilizer in the Spice language is presented. The results of modeling in static mode are presented. The simulation results are compared with experimental data and technical description of the chip manufacturer.


Author(s):  
Riccardo Caponetto ◽  
Salvatore Graziani ◽  
Emanuele Murgano

AbstractIn the paper, a fractional-order RLC circuit is presented. The circuit is realized by using a fractional-order capacitor. This is realized by using carbon black dispersed in a polymeric matrix. Simulation results are compared with the experimental data, confirming the suitability of applying this new device in the circuital implementation of fractional-order systems.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.


2012 ◽  
Vol 588-589 ◽  
pp. 614-617
Author(s):  
Zhi Hua Wang ◽  
Mei Ling Li ◽  
Jian Zhang ◽  
Li Wang ◽  
Yong Xu

The Equivalent Turn Number of Coil (ETNC) is proposed for induction coil design. Simulation results show that the vibrationonthe induction coil’s structure. The optimized coil is composed by two symmetry parts on the condition of sinusoidal vibration. The effective value of output EMF of optimized coil increases 51.39% than uniform coil’s. In the experiment, the optimized and uniform coils are fabricated with 600 turns and comparatively studied in the same vibration-to-electrical generator. The test results show that the peak-to-peak value and effective value of output EMF of the optimized coil can increase up to 52.59% and 48.76%, respectively, compared with the uniform coil.


2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.


Sign in / Sign up

Export Citation Format

Share Document