基于汽环法测量的制冷压缩机综合性能试验台设计应用

介绍了制冷压缩机综合性能试验台的设计、用途和功能,阐述了采用汽环法测量较之常规的量热法测量所具有的优越性。通过对一些实测试验参数的分析,可以看出建成的试验台具有工况稳定,测试速度快,测量能耗低,测量精度高等优点。     

基于LabVIEW的蜗杆减速器测试系统

为有效监控蜗杆减速器的制造品质,改进设计,通常要在蜗杆传动试验台上对减速器进行传动效率、噪音、温升等指标的测试.对现有的蜗杆减速器测试系统进行了改造.新设计采用虚拟仪器平台,充分发挥了计算机的处理能力,减少了硬件成本.系统测量精度高,便于实现数据分析处理和输出测试报告.     

Cavitation erosion—A survey of the literature 1940–1970

The design of a unique rig for the testing of dry running radial bearings under light load is described. Convenient adjustment of all independent parameters and their accurate measurement by electrical methods make the test machine very versatile. Preliminary results about the performances of bushes made of a special, polymer based, composite are presented.     

Generation,validation and application of dynamic load profiles in flow measurement using cavitating Herschel–Venturi nozzles

Today, utility meters for water are tested for measurement behavior at stable operating conditions at specified flow rates as part of the approval process. The measurement error that occurs during start and stop or when changing between flow rates may not be taken into account. In addition, there are new technologies whose measuring behavior under real-world conditions is only known to a limited extend. To take these facts into account, a new method has been developed and tested to determine the measurement behavior of water meters under dynamic load profiles as they occur in the real application. For this purpose, a test rig for flow rate measurement was extended by a cavitation nozzle apparatus and the generation of dynamic load profiles was validated. For the cavitation nozzles used, possible factors influencing the flow rate, such as temperature and purity of the water as well as the upstream pressure were investigated. Using different types of domestic water meters, the applicability of the dynamic test procedure was demonstrated and the measurement behavior of the meters was characterised.     

Modeling and experimental evaluation of torque loss in turbine test rig for accurate turbine performance evaluation

The performance of a turbine is evaluated through a turbine rig test by measuring the torque or power generated from the test turbine using a dynamometer or torque sensor installed in the test rig. Highly precise assessment requires accurate measurement of the torque or power. However, an intrinsic difficulty exists such that not all power generated by the turbine is measured by the dynamometer or torque sensor. A small portion of power generated from the test turbine is dissipated between the test turbine and torque sensor as bearing and windage losses. The dissipated energy is called mechanical loss of test rig. Therefore, measuring the mechanical loss of the test rig is necessary for the accurate evaluation of the turbine performance. The present paper classifies mechanical loss into bearing, disk windage, and extra windage losses. Spin-down tests are performed in a 1-stage axial turbine test rig to evaluate each loss. The total mechanical loss amounts to 0.78% to 1.4% of energy generated at the turbine. Bearing loss is dominant. Mechanical loss is dependent on and increases with decreasing bearing temperature.     

电动葫芦试验台智能测控系统研发

电动葫芦试验台是用于考核电动葫芦产品综合性能的专用大型试验设备。为得到真实、可靠、稳定的试验数据,通过结合先进的传感技术、网络技术、自动控制技术,开发了智能型电动葫芦试验台的测控系统,实现了对试验台的自动控制与智能测试。     

电液伺服控制摩托车随机疲劳试验台的研究

分析了摩托车随机疲劳试验台的基本原理与结构特点,并针对其电液伺服系统建立了一种新的疲劳模拟时域控制方法,设计了多级递阶模糊控制器来控制试验台跟踪期望输入信号,以最终实现对电液伺服系统的实时控制.最后在试验台上进行了多种规格摩托车的振动试验,试验结果证明该试验台完全满足摩托车可靠性试验要求,为摩托车零部件及整车疲劳试验提供了新的方法.     

HKD型航空润滑油本构方程的确定及拖动力计算

测量了HKD型航空润滑油的拖动力,确定了该油的本构方程,给出了本构方程中各种流变参数的计算方法并拟合出了计算公式,给出了拖动力的计算方法。结果表明:该油在试验条件下表现为粘弹性;拖动力的理论预测值与试验测量值之间误差较小,曲线形状一致,本构方程正确合理;流变参数的拟合公式精度较高。     

A test rig for testing radial diffusers

A simple test rig for investigating the performance of vaneless diffusers with diverging walls for centrifugal compressors has been designed, fabricated and satisfactorily tested. The test rig was designed to give values of area ratio from 1·5 to 6 for an included angle of 10°. A uniform flow at the entry of the diffuser had been achieved by the use of a centre body and suction on both the walls. The swirl was zero in all the tests.A maximum Reynolds' number of 2·8 × 10⁵ can be obtained during the tests. Experimental values of the coefficients for losses, the pressure recovery and efficiency were obtained from the measurements of static and stagnation pressures.     

A novel test rig for in situ and real time optical measurement of the contact area evolution during pre-sliding of a spherical contact

An experimental test rig was developed in order to investigate elastic–plastic single micro-spherical contact under combined normal and tangential loading. This novel apparatus allows in situ and real time direct optical measurement of the real contact area (RCA) evolution in pre-sliding. It also allows relative displacement measurements under very low rates of tangential loading (down to 0.01 N/s) to capture accurately the fine details at sliding inception. This is achieved by piezoelectric actuation in closed loop feedback control in addition to synchronization with data and image acquisition to obtain real time measurement. The RCA measurement is realized by direct optical observation technique, whereas two different image processing algorithms were implemented for the elastic and the elastic–plastic contact regimes. The various features and capabilities of the test rig are presented along with some preliminary experimental results of RCA and friction behavior to assess its performance.     

Computerised test-schema for the motion recognition and evaluation of a dynamic system

An interactive measurement procedure, used to perform the model identification of a multi-mass vibrating test rig, is discussed. The objective of this (secondary) observation chain is the collection of additional information on the test rig dynamic behaviour, in order to improve the accuracy of the measurements carried by the (principal) observation device. The result is obtained, recalling an original CAT code, purposely developed for the class of applications as that described in the paper.     

载货汽车车厢振动的试验分析

对载货汽车车厢在道路试验中的振动进行测试和分析，获得载货汽车车厢在各种路面下振动的时、频域信息，为市亩一厢疲劳台架试验装置和制定试验规范提供依据。     

An ultra high-pressure test rig for measurements of small flow rates with different viscosities

Within the framework of a research project regarding investigations on a high-pressure Coriolis mass flow meter (CMF) a portable flow test rig for traceable calibration measurements of the flow rate (mass - and volume flow) in a range of 5 g min⁻¹ to 500 g min⁻¹ and in a pressure range of 0.1 MPa to 85 MPa was developed. The measurement principle of the flow test rig is based on the gravimetrical measuring procedure with flying-start-and-stop operating mode. Particular attention has been paid to the challenges of temperature stability during the measurements since the temperature has a direct influence on the viscosity and flow rate of the test medium. For that reason the pipes on the high-pressure side are double-walled and insulated and the device under test (DUT) has an enclosure with a separate temperature control. From the analysis of the first measurement with tap water at a temperature of 20 °C and a pressure of 82.7 MPa an extensive uncertainty analysis has been carried out. It was found that the diverter (mainly due to its asymmetric behaviour) is the largest influence factor on the total uncertainty budget. After a number of improvements, especially concerning the diverter, the flow test rig has currently an expanded measurement uncertainty of around 1.0% in the lower flow rate range (25 g min⁻¹) and 0.25% in the higher flow rate range (400 g min⁻¹) for the measurement of mass flow. Additional calibration measurements with the new, redesigned flow test rig and highly viscous base oils also indicated a good agreement with the theoretical behaviour of the flow meter according to the manufacturers׳ specifications with water as test medium. Further improvements are envisaged in the future in order to focus also on other areas of interest.     

Case study of the electrical hardware and software for a flowmeter calibration facility

In the development of a flow test rig as a tool for investigating manufacturing variation and providing guidance to manufacturers considering setting up such a rig for calibration of meters at the end of the production line, we encountered various problems. We discussed some of these in a previous paper in Baker et al. (2006) [1]. In a subsequent paper in Shimada et al. (2010) [2] we reported on tests aimed at identifying the limits of measurement trueness of the rig and the obtainable precision (VIM (1993); Amended 1995 Supplements (1993) [3], [4]) with this type of design. In this paper we discuss the aims for signal measurement and the design, implementation of hardware and software, and the commissioning of the system. In particular, we have set out in some detail the problems encountered which we suspect are experienced by others, and the solutions found which appear to be justified by their application to a rebuilt rig with satisfactory performance.     

Development of a device for the measurement of thermal and fluid flow properties of heat exchanger materials

As yet, no standard equipment exists for the measurement of heat transfer through porous materials, such as metal foams (metals with a high volume fraction of porosity). Most research in this area has been carried out using bespoke test rigs. Here the creation of a test rig specifically developed for the measurement of the heat transfer of metal foams is reported. This method has been applied to laboratory made samples processed by replication and examples of commercially available aluminium foams (Duocel and Corevo), and should be suitable for the testing of all materials with comparable permeability. As this equipment is new and unique, the design will be discussed in detail, along with the various tests that were performed to ensure reliability and consistency with other methods and published data.     

平箔动压止推气体轴承的试验研究

本文提出了一种新型结构的箔片止推动压气体轴承，搭建了多功能止推轴承试验台，并主要针对其承载力性能进行了初步的试验研究，试验轴承的外径为φ38mm，内径为φ16mm，在11000r/min的转速下获得的最大轴向承载力为44.1N。     

自旋润滑油膜测量系统

设计制造了一种纯自旋弹流润滑油膜测量系统,介绍了其油膜厚度多光束干涉测量原理和主要的机械结构组成。初步测量结果表明接触区在纯自旋条件下可形成弹流润滑油膜,出现扇形的对称气穴区。     

基于LMS Test．1ab的压缩机管道振动测试与分析

提出了应用LMS Test．1ab进行往复压缩机管道振动测试的新方法，利用LMS Test．1ab数据采集、分析软件及相关硬件，搭建了往复压缩机管道振动测试系统，对管道系统的固有频率进行了测试，并对测试结果进行了验证，从而证实了本系统的准确性与实用性。     

推力轴承试验台异常振动故障诊断方法

针对某推力轴承试验台运行过程中的异常振动问题进行了故障诊断研究。首先,基于快速傅里叶变换方法(fast Fourier transformation,简称FFT),对实验台的异常振动信号及其特征进行了捕捉和提取;其次,从激振力、系统刚度、共振等因素对异常振动进行了专家系统故障诊断,结合有限元分析的计算结果表明,转频与试验台的动态特性发生耦合是诱发整个试验台共振的根本原因,基于此原因对试验台出现的3个异常振动特点进行了解释;最后,对试验台局部进行了优化,以避免共振发生,优化后的试验台整体动态特性可以有效避开转动频率,测试结果显示新试验台在运行工况范围内均不会出现较大的振动。