Experimental analysis of control loops with different delay times in the supply air system of a radiator test rig

2011 ◽  
Vol 43 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Yongpan Chen ◽  
Jili Zhang ◽  
Zhen Lu ◽  
Tianyi Zhao ◽  
Hui Liu
Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 848
Author(s):  
Bogdan Sapiński ◽  
Paweł Orkisz ◽  
Łukasz Jastrzębski

The aim of the work is to investigate power flows in the vibration reduction system equipped with a magnetorheological (MR) damper and energy regeneration. For this purpose, experiments were conducted in the test rig compound of the shaker and the vibration reduction system (electromagnetic harvester, MR damper, spring) which are attached to the sprung mass. The experimental data acquired under sine excitations enabled us to analyze instantaneous power fluxes, as well as a rate of inertial energy changes in the system.


2020 ◽  
Vol 2 (5) ◽  
Author(s):  
Ana Tejero‐González ◽  
Eloy Velasco‐Gómez ◽  
Manuel Andrés‐Chicote ◽  
Francisco Javier Rey‐Martínez

Author(s):  
Franck Balducchi ◽  
Mihai Arghir ◽  
Romain Gauthier

The paper deals with the experimental analysis of the dynamic characteristics of a foil thrust bearing (FTB) designed following the specifications given by NASA in 2009. The start-up characteristics of the same foil bearing were investigated in a recently published paper. The test rig used for start-up measurements was adapted for dynamic measurements. The paper presents the test rig in detail as well as its identified dynamic models. Measurements of the dynamic characteristics of the bump foil structure were performed for static loads comprised between 30 N and 150 N while measurements for the FTB were performed at 35 krpm for 30 N, 60 N and 90 N. Excitation frequencies were comprised between 150 Hz and 750 Hz. Results showed that the dynamic stiffness of the FTB increase with excitation frequency while the equivalent damping decreases. Both stiffness and damping increase with the static load but are smaller at 35 krpm compared to 0 rpm.


Author(s):  
O. Schneider ◽  
H. J. Dohmen ◽  
F.-K. Benra ◽  
D. Brillert

Improvements in efficiency and performance of gas turbines require a better understanding of the internal cooling air system which provides the turbine blades with cooling air. With the increase of cooling air passing through the internal air system, a greater amount of air borne particles is transported to the film cooling holes at the turbine blade surface. In spite of their small size, these holes are critical for blockage. Blockage of only a few holes could have harmful effects on the cooling film surrounding the blade. As a result, a reduced mean time between maintenance or even unexpected operation faults of the gas turbine during operation could occur. Experience showed a complex interaction of cooling air under different flow conditions and its particle load. To get more familiar with all these influences and the system itself, a test rig has been built. With this test rig, the behavior of particles in the internal cooling air system can be studied at realistic flow conditions compared to a modern, heavy duty gas turbine. It is possible to simulate different particle sizes and dust concentrations in the coolant air. The test rig has been designed to give information about the quantity of separated particles at various critical areas of the internal air system [1]. The operation of the test rig as well as analysis of particles in such a complex flow system bear many problems, addressed in previous papers [1,2,3]. New theoretical studies give new and more accurate results, compared to the measurements. Furthermore the inspection of the test rig showed dust deposits at unexpected positions of the flow path, which will be discussed by numerical analysis.


Author(s):  
O. Schneider ◽  
F.-K. Benra ◽  
H. J. Dohmen ◽  
K. Jarzombek

With the increase of cooling air passing through the internal air system of modern gas turbines, a greater number of airborne particles is transported to the film cooling holes in the turbine blade surface. In spite of their small size, these holes are critical for airflow and must be free of blockage. A test rig has been designed to study the quantity of separated particles at various critical areas of the internal air system. Former publications for this conference gave detailed insight into the test rig, the flow structure and the particle motion during separation. The process of separation generates abrasion on the rotating and stationary parts of the system. When considering service and maintenance or even unexpected operation faults of the gas turbine, it is important to know the location and abrasion rate of these critical areas. The flow structure within the pre-swirl cooling air system results in locally focused abrasion regions, which are investigated in this paper. New simulations, taking additional physical effects into account, are discussed in the paper. The simulation results are compared to results obtained by measurements and observations within the test rig. Qualitative and quantitative results show the ability to predict the quantity of abrasion during operation on various critical areas of the system.


Author(s):  
Fabio Burlon ◽  
Diego Micheli ◽  
Michele Simonato ◽  
Riccardo Furlanetto

Pumps used in professional appliances process a solution of water, soils residues and detergents. These affect vapor tension, viscosity and rheology of the solution, mainly due to the presence of surfactants and polymers. Only a few studies have been found on how these substances can influence pump performances. Therefore, an experimental analysis has been carried out with aqueous solutions of a detergent component, the Polyox WSR 301, in the concentration range of 100–7000 ppm, to evaluate their influence on pump performances and cavitation. Some properties of the solutions have been preliminary characterized with a rheometer. Then, each solution has been tested in a dedicated test rig, to compare the performance curves of a centrifugal pump used in professional warewashing machines with those obtained with pure water. A non-intrusive method, based on the investigation of high frequency vibrations and noise signals, has been developed to detect cavitation at its early stage of inception. It was observed that polymer mitigates cavitating pump vibrations, with a reduction of the acceleration to less than one g. The analysis has provided the data necessary for the successive development of a control strategy for pump operation in professional appliances.


Author(s):  
Lixin Zhao ◽  
Baojun Zhu ◽  
Yue Wang

Application background of gas-liquid separators is introduced. Centrifugal gas-liquid separators have many advantages, which are analyzed by comparing with normal gravity settling facilities. Experimental research was carried out. Test rig and facilities are described. Test prototypes are transparent plexi-glass separators. Through transparent prototypes, interior flow field can be observed clearly. Experimental phenomena of different structure plexi-glass prototypes are compared with and analyzed, some test photos were recorded. Test data of plexi-glass prototypes were obtained. Results show that the separating performance of the centrifugal gas-liquid separators is satisfactory. The structural scheme of high-efficient separator design is concluded.


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