Papers by Keyword: Experimental Test

Abstract: This paper presents a study on an oil-water two-phase flow model in a downhole Venturi meter by theoretical calculation, numerical simulation and experimental testing. The flow field and pressure characteristics with different flow and oil-water ratios in Venturi tube are investigated. It is found that the flow is stratified in the Venturi tube, the water phase accumulates in the tube center and the oil phase concentrates on the wall; the pressure drop is increased with flow; theoretical and numerical results are verified by experimental data.

Abstract: This paper presents a numerical simulation and experimental study on a solid-liquid hydrocyclone. In the simulation, the standard k-ε turbulence model and the zero-equation model are employed to compute the flow field of the two phases in the hydrocyclone under different conditions, such as viscosity of the liquid, particle size and flow rate. In the experiment, a hydrocyclone is manufactured and measured for the separation efficiency and pressure drop in the test system. The simulation result of hydrocyclone performance matches well with the experimental data.

Abstract: The active safety issue of rail vehicles is important for providing regular transportation services and minimizing the risk of accidents. One of the solutions to the problem of assuring high level of active safety is applying the condition monitoring of suspension system. Suspension, as a part of running gear, is crucial for providing proper running behavior stability. The increasing demands on improving safety of railway transport has led to development of prototype of rail vehicles' suspension monitoring system at Monitoring of Technical State of Construction and Evaluation of its Lifespan Project (MONIT). The idea of the system is qualitative assessment of suspension condition based on acceleration signals measured on bogie frames, wheels and body. The monitoring system prototype has been tested on passenger and freight cars in two states of suspension condition: nominal and damaged. Experimental tests have been performed on experimental track near Zmigrod in Poland. This paper presents analysis of the results obtained from the tests of the rail vehicles' suspension monitoring system prototype.

Abstract: In this paper we present the cold extrusion shaping technology of 20Cr bevel gears. First, we analyzed a series of processing and treatment referring to bevel gear cold extrusion technology and calculated the cold extrusion pressures used for mold design; then, we designed and cold extruded two- or three-ring composite cold extrusion dies with its precise guiding device; and last, we experimentally tested our designed and extruded bevel gear. The results showed that 20Cr bevel gears shaped with cold extrusion have qualified properties and satisfy application requirements within the required error range. This research is of significance in actual cold extrusion production.

Abstract: This paper demonstrates how advanced composite materials as F.R.C.M. (fiber reinforced cementicius matrix) can offer high advantages for repairing ageing infrastructures. The FRCM strengthening system can be considered alternative to the well-known fibre-reinforced polymers (FRP) system. The FRCM system, in fact, permits the elimination of some disadvantages related to the use of organic resin, such as lack of fire resistance and low compatibility with the concrete substrate. In this study, a data comparison between non-reinforced and reinforced models is discussed. The specimens simulated a part of a bridge deck to repair or strengthen. The samples were no. 6 plates 70x70 cm ² long and 10 cm thick realized by a mix design concrete [1] of 30/35 class and reinforced by steel bars. The strengthening system consists in applying the composite biaxial sheet at the intrados of the deck in two layers orthogonal to each other.

Abstract: Compound condensing heat pump combines the advantages of heat pump technology and condensing heat recovery technology. It takes full account of the common infrastructure in the cooling and heat source system and greatly increases equipment utilization ratio. It also recycles condensing heat to produce sanitary hot water efficiently while ensuring cooling and heating of heat pump to achieve the same effect. The distinctive technical features of the compound condensation / evaporation of four functional heat pump ensure its efficient and reliable operation. This heat pump system runs in several models throughout the year,which include the refrigeration mode, refrigeration&domestic hot water mode, domestic hot water mode and heating mode. The performance in refrigeration mode and refrigeration&domestic hot water mode is studied by a designed experiment is done and the an explicit analysis is made. By comparing the results of simlation and experiment,an agreement can be shown clearly. Therefore,the final conclusion is drawn:the performance of compound condensation / evaporation of four functional heat pump is improved over the traditional heat pump.It is worthy to further promote for the sake of energy saving.

Abstract: The stress-strain of triaxial rheological test for rock can be divided into three stages: initial attenuation rheological stabilization rheoligical and speedup rheological stages, the damage is rapid increased in the speedup stage. Damage mechanics is introduced into the Nishihara rheological model, a new rheological constitutive model is established which is combined with the concept of effective stress. The mechanical parameters are recognized by the experimental test data of greenschist. Computing result shows that, the presented model can described the mechanical characteristics in different rheological stage very well, and the error between simulated result and test data is small.

Abstract: LNR and LRB in which the value of shear modulus of inner rubber is 0.392MPa have been widely used in the practical isolation projects, although there are some test researches about dependency of shear property of them, but there is little complete study under high design compressive stress, such as 15MPa, and equations of dependency of shear property of them have seldom been found. In this paper, completely experiments about dependency of shear property of them have been done, and the fitted equations about various dependencies for LNR and LRB are given. Effect of size of rubber bearing on various dependencies is also studied. Formulas of determination of parameters in bilinear model of LRB are proposed, and have been testified well with FEA program.

Abstract: The trends in automobile industry always include the use of new materials such as those needed for the passive safety of vehicles and they are one of the most important strategies to reduce injury of passengers during traffic accidents. Associated with the development of security systems, there is the possibility of improving efficiency by the introduction of materials that lead to weight reduction, having a direct impact on fuel consumption and lower carbon emissions. The present work aims to study the behaviour of sandwich structures, composed by a foam core with two outer layers of metal sheet (all structure being aluminium). The study of the composite structure behaviour, its mechanical characterization and numerical modelling is essential to analyse the mechanical performance of structures based on this type of materials. This step is fundamental in preliminary design, since the different materials of the composite structure show different mechanical responses. The differences in mechanical behaviour are demonstrated by the axisymmetric compressive stress states tests and also by the influence of hydrostatic pressure in the yield of the aluminium foam porous material, while the yield of the homogeneous solid material (aluminium sheet) can be considered as pressure insensitive. In order to correctly characterize separately these two materials of the composite (outer layers and core), a set of tests were performed. The characterization of the aluminium sheet was performed in a series of tensile tests, using three different rolling directions. For the metal foam core characterization a series of uniaxial compression tests were performed. The experimentally obtained results were applied in the development of numerical models for this kind of sandwich structure. The models include elastoplastic constitutive relation, where a distinct plastic domain for different materials is accounted for, as well as, the influence of hydrostatic pressure in the yield of the porous material. Also, the validation of the elastoplastic models is performed by comparing results obtained by numerical simulations with those obtained experimentally.

Abstract: Fuel cell vehicle has been studied to improve emission and vehicle performance. The limitations of fuel cell vehicles, including high costs, limited accelerating competence and inadequate driving range must be improved so that they will be widely accepted by the consumer market. Better understanding on the underlying mechanisms of fuel cell vehicles and adequate optimization tools for designing their power train systems is much needed. This work focuses on the key issues through the simulating and experimental tests of fuel cell vehicle using a custom made dynamometer, a fuel cell scooter, which serve as generic, but easy to operate equipment to validate new computer models and modeling methods for fuel cell vehicles. The results support better understanding on fuel cell vehicle performance modeling. Based upon the new and validated models, design optimization is carried out for the fuel cell vehicle. The study and its results can be used in the development and evaluation of various fuel cell vehicles.