Design and Development of Hydrodynamic Lubricating System of Large-Scale Mill Oil-Film Bearing Test Rig

2010 ◽  
Vol 145 ◽  
pp. 274-277 ◽  
Author(s):  
Jian Mei Wang ◽  
Qing Xue Huang ◽  
Jian Zhao Sun ◽  
Xue Tao
Keyword(s):  
Large Scale ◽  
Design Parameters ◽  
Test Rig ◽  
Detailed Design ◽  
Oil Film ◽  
Solid Models ◽  
Critical Segment ◽  
3D Solid ◽  
Good Operation ◽  
Lubricating Mechanism

The lubricating system is the critical segment to ensure the good operation of bearing subsystem and the whole mill system. To keep pace with the advanced domestic and outdoors technologies, it is emergent to design and develop the mechatronic test rig of mill oil-film bearing. According to the detailed design parameters and design principles of lubricating system, its main modules and the lubricating mechanism are designed and implemented. The according 2D drawings and 3D solid models are successfully established. Consequently, the prototype is developed, and runs well in practical tests on mechanical parameters of mill bearing. Moreover, some further improvements are also made to better the performances of lubricating system.

Design Parameters of Brush Seals and Their Impact on Seal Performance

2012 ◽  
Author(s):  
H. Schwarz ◽  
J. Friedrichs ◽  
J. Flegler
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Large Scale ◽  
Design Parameters ◽  
Test Rig ◽  
Pressure Drops ◽  
Seal Design ◽  
Brush Seal ◽  
Extreme Load ◽  
Brush Seals

Brush seals, which were originally designed for gas turbine applications, have been successfully applied to large-scale steam turbines within the past decade. From gas turbine applications, the fundamental behavior and designing levers are known. However, the application of brush seals to a steam turbine is still a challenge. This challenge is mainly due to the extreme load on the brush seal while operating under steam. Furthermore, it is difficult to test brush seals under realistic conditions, i.e. under live steam conditions with high pressure drops. Due to these insufficiencies, 2 test rigs were developed at the University of Technology Braunschweig, Germany. The first test rig is operated under pressurized air and allows testing specific brush seal characteristics concerning their general behavior. The knowledge gained from these tests can be validated in the second test rig, which is operated under steam at pressure drops of 45 bar and temperatures up to 450 °C. Using both the air test rig and the steam test rig helps keep the testing effort comparably small. Design variants can be pre-tested with air, and promising brush seal designs can consequently be tested in the steam seal test rig. The paper focuses on a clamped brush seal design which, amongst others, is used in steam turbine blade paths and shaft seals of current Siemens turbines. The consequences of the brush assembly on the brush appearance and brush performance are shown. The clamped brush seal design reveals several particularities compared to welded brushes. It could be shown that the clamped bristle pack tends to gape when clamping forces rise. Gapping results in an axially expanding bristle pack, where the bristle density per unit area and the leakage flow vary. Furthermore, the brush elements are usually assembled with an axial lay angle, i.e. the bristles are reclined against the backing plate. Hence, the axial lay angle is also part of the investigation.

Practical Considerations in Designing Large Scale “Beam Down” Optical Systems

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Akiba Segal ◽  
Michael Epstein
Keyword(s):  
Large Scale ◽  
Maximum Energy ◽  
Optical Systems ◽  
Energy Concentration ◽  
Design Parameters ◽  
Weizmann Institute ◽  
Detailed Design ◽  
Working Temperature ◽  
Compound Parabolic Concentrator ◽  
Current Mirrors

The “beam down” optics or “solar tower reflector” has been successfully used recently for testing in different projects at the Weizmann Institute of Science. There are currently sufficient data on this technology to evaluate its upscaling for commercial uses. The sizing of a tower reflector (TR) is directly linked to the layout of the heliostat field and the geometry of the ground secondary concentrator (compound parabolic concentrator (CPC)). It depends on its position relative to the aim point of the field, amount of spillage around it, and the allowable solar flux striking the TR. Its position influences the size of the image at the entrance plane of the ground CPC and the spillage around the CPC aperture. The spillage around the CPC is also directly related to the exit diameter of the CPC (equal to the entrance opening of the solar reactor, matching the CPC exit) and therefore linked to the input energy concentration, thermal losses, and working temperature in the reactor. Restrictions on the size of the exit of the CPC can influence the entire design of the optical system. This paper provides the correlations between the main design parameters and their sensitivity analysis. These correlations are based on edge-ray methodology, which provides a quick and sufficiently accurate means for preliminary evaluating large-scale beam down solar plants without the need for detailed design of the heliostat field and considering their errors. The size of the TR and the geometry of the CPC are correlated to the size of the reflective area of the heliostats field (and the power output). Thermal modeling of the TR has been performed, showing the maximum energy flux allowed on the reflector to avoid overheating, using natural cooling to the surrounding air. The current mirrors of the TR are limited to working temperatures of 120–130°C to achieve reasonable lifetime. This parameter must be considered when determining the TR position. A key issue discussed in this paper is the amount of spillage around the CPC entrance. To reduce the spillage losses, one needs to increase the size of the exit aperture (although there are practical limitations to this, e.g., due to the size of the reactor’s window). This, however, reduces the concentration and increases the thermal losses from the reactor and requires optimization work.

Midsurface Abstraction From 3D Solid Models for Engineering Analysis

1996 ◽  
Author(s):  
Mohsen Rezayat
Keyword(s):  
Feature Recognition ◽  
Analysis Model ◽  
Thin Sections ◽  
New Approach ◽  
Solid Models ◽  
Product And Process ◽  
Plastic Parts ◽  
3D Solid ◽  
User Friendly ◽  
Analysis Models

Abstract An integral part of implementing parallel product and process designs is simulation through numerical analysis. This simulation-driven design requires discretization of the 3D part in an appropriate manner. If the part is thin or has thin sections (e.g., plastic parts), then an analysis model with reduced dimensionality may be more accurate and economical than a standard 3D model. In addition, substantial simplification of some details in the design geometry may be beneficial and desirable in the analysis model. Unfortunately, the majority of CAD systems do not provide the means for abstraction of appropriate analysis models. In this paper we present a new approach, based on midsurface abstraction, which holds significant promise in simplifying simulation-driven design. The method is user-friendly because very little interaction is required to guide the software in its automatic creation of the desired analysis model. It is also robust because it handles typical parts with complex and interacting features. Application of the method for feature recognition and abstraction is also briefly discussed.

scholarly journals Comparative Analysis for Internal Fixations of Pauwels II by Biomechanical Finite Element Method

2019 ◽  
Vol 103 (9-10) ◽  
pp. 493-504
Author(s):  
Matthew Jian-Qiao Peng ◽  
Xiangyang Ju ◽  
Hai-Yan Chen ◽  
Bai Bo ◽  
XinXu Li
Keyword(s):  
Finite Element ◽  
South Carolina ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
3D Models ◽  
Secondary Fracture ◽  
Solid Models ◽  
Neck Fracture ◽  
Hip Screw ◽  
3D Solid

Purpose: A series models of surgical internal fixation for femoral neck fracture of Pauwels II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Method: Seventeen specimens of proximal femurs scanned by computed tomography in Digital Imaging and Communications in Medicine (DICOM) format were input onto Mimics rebuilding 3D models; their stereolithography (STL) format dataset were imported into Geomagic Studio (3D Systems, Rock Hill, South Carolina) for simulative osteotomy and non-uniform rational basis spline kartograph; the generated IGS dataset were interacted by UG to fit simulative 3D-solid models; 3 sorts of internal fixators were expressed in 3D model by ProE (PTC, Boston, Connecticut) program virtually. Processed by HyperMesh (Altair, Troy, Michigan), all compartments (fracture model + internal immobilization) were assembled onto 3 systems actually as: Dynamic hip screw (DHS) / Lag screw (LS) / DHS+LS. Eventually, a numerical model of finite elemental analysis was exported to ANSYS for solution. Result: Three models of internal fixations for femoral neck fracture of Pauwels II were established and validated effectively, the stress and displacement of each internal pin were analyzed, the advantages of each surgical therapy for femoral neck fracture of Pauwels II were compared and demonstrated synthetically as: “The contact stress of 3-LS-system was checked to be the least; the interfragmentary displacement of DHS+1-LS assemblages was assessed to be the least.” Conclusion: 3-LS-system is recommended to be a clinical optimization for Pauwels II femoral neck facture, by this therapeutic fixation mechanically, breakage of fixators, or secondary fracture rarely occurs.

A Design Tool for Producing 3D Solid Models from Sketches

2004 ◽  
Author(s):  
Timothy M. Boundy ◽  
Gary J. McCarty ◽  
James F. Szatkowski ◽  
Nicholas A. Vitale
Keyword(s):  
Design Tool ◽  
Solid Models ◽  
3D Solid

scholarly journals Analysis of Site Selection and Design Example of Spoil Ground

2021 ◽  
Vol 631 (1) ◽  
pp. 012005
Author(s):  
Liheng Zhang ◽  
Yi He ◽  
Jie Chen
Keyword(s):  
Site Selection ◽  
Large Scale ◽  
Drainage System ◽  
Not Given ◽  
Detailed Design ◽  
Engineering Construction ◽  
Key Points ◽  
Selection Principles ◽  
Secondary Disasters ◽  
Negative Impacts

Abstract As an auxiliary project of engineering construction, spoil ground is often not given enough attention. Unreasonable spoiled materials not only have negative impacts on the local natural environment, but also generate the risk of secondary disasters. The selection and design of spoil ground is an important part of earthwork. And thus it is necessary to select the site of spoil ground reasonably and carefully and carry out detailed design of spoil, protection and flood drainage. First of all, the basic selection principles of spoil ground were discussed in this paper. Then, combined with the spoil ground design of the Heat and Power Cogeneration Power Workshop Project in Zhenfeng County's Coal, Electricity and Metallurgical Integration Industrial Park, the author presented elaboration of the technical key points of site selection, slope stability, blocking engineering and flood drainage system of large-scale spoil ground. The analysis in this paper can be used as a reference for similar spoil ground design.

scholarly journals Influence of pipeline geometry on hydrodynamics and heat transfer processes by an example of a ship steam generator

2021 ◽  
Vol 2088 (1) ◽  
pp. 012033
Author(s):  
O V Mitrofanova ◽  
A V Fedorinov
Keyword(s):  
Nuclear Power ◽  
Large Scale ◽  
Complex Geometry ◽  
Swirling Flow ◽  
Thermal Power ◽  
Design Parameters ◽  
Nuclear Power Installation ◽  
Wide Range ◽  
Nuclear Power Installations ◽  
Power Installations

Abstract The theoretical and computational analysis proposed in this work is aimed at identifying the features of thermal and hydrodynamic processes carried out in the steam-generating channels of the ship type water-moderated nuclear power installations. It is shown that the complex geometry of the thermohydraulic tract curvilinear channels of the steam generating system has a significant effect on the efficiency of the transport nuclear power installation. In addition to the formation of large-scale vortex structures and swirling flow in the pipeline, the phenomenon of the swirling flow crisis is revealed, under which the low-frequency component of the acoustic spectrum is enhanced. The scientific and applied significance of the proposed research is associated with the need to ensure a wide range of operational changes in efficient and safe operation power modes of icebreaker nuclear power installations. The research, aimed at developing the principles of physical and mathematical modeling of complex vortex flows, is necessary to optimize the design parameters of the thermal power equipment elements of new generation ship nuclear power installations in order to ensure increased safety and reliability of their operation.

Analysis of Tribological Performance of Piston Ring Lubrication

2011 ◽  
Author(s):  
Yibin Guo ◽  
Wanyou Li ◽  
Dequan Zou ◽  
Xiqun Lu ◽  
Tao He
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Power Loss ◽  
Piston Ring ◽  
Design Parameters ◽  
Oil Film ◽  
Starved Lubrication ◽  
Piston Ring Lubrication ◽  
Cylinder Bore ◽  
Lubrication Conditions

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.

Fixed-Bed Adsorption Column Studies for the Removal of Methyl Orange from Water Using Polyethyleneimine-Graphene Oxide Polymer Nanocomposite Beads

2021 ◽  
Vol 891 ◽  
pp. 31-36
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Camille Margaret S. Alvarillo ◽  
Joshua L. Chua ◽  
Ysabel Marie C. Gonzales ◽  
Jem Valerie D. Perez
Keyword(s):  
Graphene Oxide ◽  
Methyl Orange ◽  
Large Scale ◽  
Scale Up ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Design Parameters ◽  
Column Studies ◽  
Fixed Bed Column ◽  
Adsorption Column

Continuous fixed-bed column studies were performed using nanocomposite beads made up of chitosan, polyethyleneimine, and graphene oxide as adsorbents for the removal of methyl orange (MO) in water. The effects of different operating parameters such as initial MO concentration (5, 10, and 15 ppm), bed height (10, 17.5, and 25 cm), and flow rate (27, 43, and 58 mL/min) were investigated using an upward-flow fixed-bed column set-up. The breakthrough curves generated were fitted with Adams-Bohart, Thomas, Yoon-Nelson, and Yan et al. models. The results showed that Yan et al. model agreed best with the breakthrough curves having an R2 as high as 0.9917. Lastly, design parameters for a large-scale adsorption column were determined via scale-up approach using the parameters obtained from column runs.

Sign in / Sign up

Export Citation Format

Share Document