scholarly journals Dynamic Modeling and Full-Process Simulation of the Core Engine Test Rig Main Test System

2021 ◽  
Vol 11 (23) ◽  
pp. 11213
Author(s):  
Ze-Zheng Jia ◽  
Yang Chen ◽  
Ye-Jun Wang ◽  
Zhen-Qi Sun ◽  
Yu-Long Huang

As a virtual digital model that can reflect physical entities or systems, digital twins are revolutionizing industry. The first prerequisite for the construction of digital twins is the establishment of high-precision and complex entities or system models. A 47-components numerical system is established for the core engine test rig main test system by using the finite volume modularization modeling method. A comprehensive solution to the system-level valve-spool/orifice throttling modeling, the key issue of the fluid pipeline system modeling, is presented, and the algorithms of throttling and mixing are deepened and expanded. The full-process simulation study on two tests of normal-temperature 1400 s and low-temperature 1240 s shows that the combined regulation of five regulator valves and the change of cold source directly decide dynamic change of the system in each stage; the simulation reveals the phenomena such as the gas cylinder cooling with deflation, the air cooling when expanding from main pipeline to two branch pipelines, shunting flow by branch pipeline, and the cold and hot gases mixing; the overall variation trends of the simulation curves are consistent with those of all the experimental curves of the test rig normal-temperature/low-temperature air supply lines, exhaust bypass, and engine main line in two operating conditions, and the maximum error between simulation curves and test curves of pressure, total pressure, and total temperature is less than 12%. The numerical system can be used for the construction of virtual models of digital twins, and the modeling method provides a feasible solution to the key technology of digital twins.

Author(s):  
Deepak Trivedi ◽  
Eric Ruggiero ◽  
Christopher Wolfe ◽  
Joel Kirk ◽  
John Williams ◽  
...  

Abstract Test facilities capable of simulating relevant operational environments for validating novel concepts are indispensable for advancing the state-of-the-art in turbomachinery sealing technology. A test rig suitable for demonstrating full-scale rotor-stator sealing concepts under operational environments relevant for a variety of turbomachinery gas paths was designed and commissioned at GE’s Seals Test Facility. The test rig, called the Advanced Seals Test Rig (or ASTR), can simulate conditions that include a range of rotor speeds, fluid pressures and temperatures, from steady state operating conditions of high pressure turbines of aircraft engines to sections of steam turbines. The present paper provides a system level description of the test rig. The main test section of the rig is housed within the centerpiece of a stamped pressure vessel. A drive train penetrates the pressure vessel and consists of an integral saddle mounted rotor. A motor connected to a high-speed gearbox through couplings on each end permits rotation of the test rotor. The test rotor is supported by two bearing pedestals. The paper describes these rig subsystems with focus on novel features for ease of operation. Key instrumentation and operating procedures that enable the rig to operate safely are also described. Key drivers of the rig design, such as test requirements, rotordynamics, mechanical design, ergonomics, safety and test productivity are outlined. Mechanical design considerations include strict requirements for thermal and pressure deformation under demanding conditions of pressure and temperature. Commissioning of the rig included phases of fabrication, installation, shakeout, calibration and benchmarking. Key learnings from the rig design and commissioning process, as well as operations, are summarized.


Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
Q. Kim ◽  
S. Kayali

Abstract In this paper, we report on a non-destructive technique, based on IR emission spectroscopy, for measuring the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field effect transistor (MESFET). A submicron-size He-Ne laser provides the local excitation of the gate channel and the emitted photons are collected by a spectrophotometer. Given the state of our experimental test system, we estimate a spectral resolution of approximately 0.1 Angstroms and a spatial resolution of approximately 0.9 μm, which is up to 100 times finer spatial resolution than can be obtained using the best available passive IR systems. The temperature resolution (<0.02 K/μm in our case) is dependent upon the spectrometer used and can be further improved. This novel technique can be used to estimate device lifetimes for critical applications and measure the channel temperature of devices under actual operating conditions. Another potential use is cost-effective prescreening for determining the 'hot spot' channel temperature of devices under normal operating conditions, which can further improve device design, yield enhancement, and reliable operation. Results are shown for both a powered and unpowered MESFET, demonstrating the strength of our infrared emission spectroscopy technique as a reliability tool.


2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.


Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Peyghami ◽  
Tomislav Dragicevic ◽  
Frede Blaabjerg

AbstractThis paper proposes a long-term performance indicator for power electronic converters based on their reliability. The converter reliability is represented by the proposed constant lifetime curves, which have been developed using Artificial Neural Network (ANN) under different operating conditions. Unlike the state-of-the-art theoretical reliability modeling approaches, which employ detailed electro-thermal characteristics and lifetime models of converter components, the proposed method provides a nonparametric surrogate model of the converter based on limited non-linear data from theoretical reliability analysis. The proposed approach can quickly predict the converter lifetime under given operating conditions without a further need for extended, time-consuming electro-thermal analysis. Moreover, the proposed lifetime curves can present the long-term performance of converters facilitating optimal system-level design for reliability, reliable operation and maintenance planning in power electronic systems. Numerical case studies evaluate the effectiveness of the proposed reliability modeling approach.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 164
Author(s):  
Jianwei Shao ◽  
Cuidong Xu ◽  
Ka Wai Eric Cheng

The rail transit system is a large electric vehicle system that is strongly dependent on the energy technologies of the power system. The use of new energy-saving amorphous alloy transformers can not only reduce the loss of rail transit power, but also help alleviate the power shortage situation and electromagnetic emissions. The application of the transformer in the field of rail transit is limited by the problem that amorphous alloy is prone to debris. this paper studied the stress conditions of amorphous alloy transformer cores under different working conditions and determined that the location where the core is prone to fragmentation, which is the key problem of smoothly integrating amorphous alloy distribution transformers on rail transit power supply systems. In this study, we investigate the changes in the electromagnetic field and stress of the amorphous alloy transformer core under different operating conditions. The finite element model of an amorphous alloy transformer is established and verified. The simulation results of the magnetic field and stress of the core under different working conditions are given. The no-load current and no-load loss are simulated and compared with the actual experimental data to verify practicability of amorphous alloy transformers. The biggest influence on the iron core is the overload state and the maximum value is higher than the core stress during short circuit. The core strain caused by the side-phase short circuit is larger than the middle-phase short circuit.


e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 200-209
Author(s):  
Caiyun Zhang ◽  
Chunhong Li ◽  
Bolin Ji ◽  
Zhaohui Jiang

Abstract A fast, simple, and energy-saving microwave-assisted approach was successfully developed to prepare carbon microspheres. The carbon microspheres with a uniform particle size and good dispersity were prepared using glucose as the raw material and HCl as the dehydrating agent at low temperature (90°C) in an open system with the assistance of microwave heating. The carbon microspheres were characterized by elemental analysis, XRD, SEM, FTIR, TG, and Raman. The results showed that the carbon microspheres prepared under the condition of 18.5% (v/v) HCl and heating for 30 min by microwave had a narrow size distribution. The core–shell structure of the carbon core and TiO2 shell was prepared with (NH4)2TiF6, H3BO3 using the microwave-assisted method. The hollow TiO2 microspheres with good crystallinity and high photocatalytic properties were successfully prepared by sacrificing the carbon microspheres.


2011 ◽  
Vol 148-149 ◽  
pp. 388-392
Author(s):  
Jie Du ◽  
Chun Ting Ma

Based on Interaction energy of solid ball, the new particle damper is designed which can be used in a high temperature and high shock energy. To verify the design of the damper, a falling weight Impact test rig is designed, a sensor, data acquisition card and computer hardware constitutes a signal test system. Experimental results show that the particle diameter is the biggest impact for the role of the particle damper , the characteristics of the displacement curves are increased at first and then decreased, the opposite effect of the time. At the same time filled with particles and the degree of damping rod embedment also have an impact on energy consumption.


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