scholarly journals Theoretical and Practical Aspects of Pneumatic Powder Injection into Liquid Alloys with a Non-Submerged Lance

2014 ◽  
Vol 59 (2) ◽  
pp. 731-734 ◽  
Author(s):  
J. Jezierski ◽  
K. Janerka ◽  
M. Stawarz
Keyword(s):  
Liquid Alloy ◽  
High Speed ◽  
Computer Modelling ◽  
Cone Angle ◽  
Powder Injection ◽  
New Approach ◽  
Injection Process ◽  
Metallurgical Processes ◽  
Submerged Lance ◽  
Alloy Volume

Abstract The method of powder injection into molten metal has been widely known since tens of years and successfully utilized in various metallurgical processes. The most common is a solution with injection lance submerged under the liquid alloy surface, because it is easier apart from some of disadvantages of this approach. In this paper the authors’ complex experiments on the pneumatic injection process with non-submerged lance have been presented. The new approach on jet cone angle importance and its influence on the efficiency of the injection process has been shown. The issue of the effective jet radius that was proposed by former scientists as well as computer modelling and injection experiments recorded with high speed camera have been presented. The final comparison of the typical injection lance and developed by authors new lance with flange was presented, too. The benefits of use of a new one for the treatment of small liquid alloy volume (e.g. inoculation or alloys addition introduction) have been pointed.

Two-Phase Jet in Process of Pneumatic Powder Injection into Liquid Alloy

2012 ◽  
Vol 622-623 ◽  
pp. 447-451 ◽  
Author(s):  
Jan Jezierski ◽  
Krzysztof Janerka
Keyword(s):  
High Speed ◽  
Mass Concentration ◽  
Process Analysis ◽  
Short Description ◽  
Powder Injection ◽  
Two Phase ◽  
New Approach ◽  
Injection Process ◽  
University Of Technology ◽  
Powder Particles

The short description of the new approach to the pneumatic powder injection process analysis was presented in the article. The experiments with the high speed camera recording of the two-phase jet in pneumatic powder injection process were carried out in the Department of Foundry, Silesian University of Technology, Poland. The results were briefly analyzed and some interesting conclusions appeared, especially that the real velocity of the injected particles is far less than it is normally calculated with use of the well-known formulas. They were compared with existing literature data as well as with some experimentspreviously made by authors. Powder particles velocity and two-phase jet mass concentration were analyzed as the most important parameters for powder injection process. The results described are part of the complex experimental plan and the next step is computer modeling (just launched) of the jet introducing liquid.

Optimization of Hot Press Forging Parameters in Direct Recycling of Aluminium Chip (AA 6061)

2014 ◽  
Vol 622-623 ◽  
pp. 223-230 ◽  
Author(s):  
Mohd Amri Lajis ◽  
S.S. Khamis ◽  
N.K. Yusuf
Keyword(s):  
High Speed ◽  
Sustainable Manufacturing ◽  
Hot Press ◽  
Process Technology ◽  
Primary Metal ◽  
New Approach ◽  
Mechanical And Physical Properties ◽  
Recycling Technique ◽  
Metallurgical Processes ◽  
Develop Mathematical Model

This study introduces a new approach of direct recycling using the hot press forging process that eliminates the two intermediate processes of cold-compact and pre-heating. This method leads to low energy consumption without intervening the metallurgical processes. In this study, the optimum of machined chips from high speed milling is recycled by hot press forging. The mechanical properties and surface integrity of the different chips were investigated. The performance of recycled aluminium AA 6061 chips in the mechanical and physical properties were compared with the original aluminium billet. Response surface methodology (RSM) was used to develop mathematical model of the effects on pre-compaction cycle, holding time and suitable pressure significant to the process. It is hoped that, utilization of primary metal could be fully utilized by direct recycling technique (hot press forging) introduced in this study and at the same time developing a sustainable manufacturing process technology for future needs.

The Effects of Ester Structure on Transient Fuel Spray Characteristics Including Novel Image Analysis to Quantify Air Entrainment

2015 ◽  
Author(s):  
Luis G. Gutierrez ◽  
Mohammad Fatouraie ◽  
Steve B. Xiao ◽  
Margaret S. Wooldridge ◽  
Dong Han ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
High Speed ◽  
Penetration Rate ◽  
Cone Angle ◽  
Air Entrainment ◽  
Fuel Injector ◽  
Spray Characteristics ◽  
Spray Cone ◽  
Penetration Distance ◽  
Injection Process

Achieving efficient and clean combustion of biodiesel as a renewable source of energy requires a fundamental understanding of the effects of the different thermophysical properties on the fuel injection process at conditions relevant to diesel engines. In this study, the spray characteristics of two fatty acid esters, methyl oleate and ethyl oleate, are compared to a baseline diesel fuel using high-speed imaging of the sprays in a constant volume chamber. A single hole fuel injector with a nozzle diameter of 280 μm was used with a single injection event with a duration of 1.0 ms. The spray development was investigated for fuel-rail pressures of 40, 60, 80 and 100 MPa and the chamber gas densities of 1.15 kg/m3, 5.75 kg/m3 and 11.5 kg/m3. High-speed shadowgraph imaging of the non-vaporizing sprays was performed at 15,000 frames per second. Image processing algorithms were developed to quantify the spray penetration distance, penetration rate and cone angle as a function of time for the injection process. Penetration distance and penetration rate results were similar for the esters and diesel fuel for the range of experimental conditions studied. However, diesel had a larger spray cone angle compared to both esters. Additionally a novel metric for air entrainment was developed based on the macro-scale features of the spray. The integrated mixing volume metric showed no difference in air entrainment between the fuels, which is in good agreement with the behavior expected based on spray theory.

Yaw Galloping of a TLWP Platform Under High Speed Currents by Analytical Methods and its Comparison With Experimental Results

2017 ◽  
Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes
Keyword(s):  
High Speed ◽  
Production Systems ◽  
Experimental Tests ◽  
Experimental Results ◽  
Analytical Methodology ◽  
New Approach ◽  
Laboratory Facilities ◽  
Polynomial Curve ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.

scholarly journals A New Approach to Assess the Quality of Small High-Speed Centrifugal Fans Using Noise Measurement

1999 ◽  
Vol 5 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Dingjun Cui ◽  
Ian A. Craighead
Keyword(s):  
Signal Processing ◽  
Quality Assessment ◽  
Condition Monitoring ◽  
High Speed ◽  
Noise Levels ◽  
New Approach ◽  
Commercial Market ◽  
Centrifugal Fans ◽  
Special Approach

The requirements for a special approach for the quality assessment of small high-speed centrifugal fans are outlined and a new parameter designating the noise levels from the product in comprehensive form will be discussed and described as a criterion for such quality assessment.By applying techniques of signal processing and condition monitoring, the sources of the vibration and noise in different sections of the product can be identified, then the noise from each source from different components can be determined. Using this criterion, more aspects of the quality of the products can be assessed and suggestions to improve the quality of the products can be made. Finally, the assessment of a number ofvacuum cleaner motor/fan units available in the commercial market will be presented and compared with conventional specifications. It will be shown that the new parameter provides a more useful indication of appliance quality.

scholarly journals A Study on the Sintering Behavior of T42 High Speed Steel by Powder Injection Molding (PIM) Process

2012 ◽  
Vol 19 (2) ◽  
pp. 117-121 ◽  
Author(s):  
Dong-Wook Park ◽  
Hye-Seong Kim ◽  
Young-Sam Kwon ◽  
Kwon-Koo Cho ◽  
Su-Gun Lim ◽  
...  
Keyword(s):  
Injection Molding ◽  
High Speed ◽  
High Speed Steel ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Sintering Behavior

scholarly journals Quasi-two-dimensional approximation for numerical simulation of flows in engine ducts

2019 ◽  
Author(s):  
V. Vlasenko ◽  
A. Shiryaeva
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Three Dimensional ◽  
Preliminary Design ◽  
Two Dimensional ◽  
Combustion Chambers ◽  
New Approach ◽  
One Dimensional ◽  
Dimensional Approximation ◽  
3D Flows

New quasi-two-dimensional (2.5D) approach to description of three-dimensional (3D) flows in ducts is proposed. It generalizes quasi-one-dimensional (quasi-1D, 1.5D) theories. Calculations are performed in the (x; y) plane, but variable width of duct in the z direction is taken into account. Derivation of 2.5D approximation equations is given. Tests for verification of 2.5D calculations are proposed. Parametrical 2.5D calculations of flow with hydrogen combustion in an elliptical combustor of a high-speed aircraft, investigated within HEXAFLY-INT international project, are described. Optimal scheme of fuel injection is found and explained. For one regime, 2.5D and 3D calculations are compared. The new approach is recommended for use during preliminary design of combustion chambers.

scholarly journals Modal Kinematic Analysis of a Parallel Kinematic Robot with Low-Stiffness Transmissions

Robotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 132
Author(s):  
Paolo Righettini ◽  
Roberto Strada ◽  
Filippo Cortinovis
Keyword(s):  
High Speed ◽  
Parallel Robots ◽  
Maximum Speed ◽  
Kinematic Structure ◽  
End Effector ◽  
New Approach ◽  
Working Space ◽  
Modes Of Vibration ◽  
Parallel Kinematic ◽  
Actuated Joints

Several industrial robotic applications that require high speed or high stiffness-to-inertia ratios use parallel kinematic robots. In the cases where the critical point of the application is the speed, the compliance of the main mechanical transmissions placed between the actuators and the parallel kinematic structure can be significantly higher than that of the parallel kinematic structure itself. This paper deals with this kind of system, where the overall performance depends on the maximum speed and on the dynamic behavior. Our research proposes a new approach for the investigation of the modes of vibration of the end-effector placed on the robot structure for a system where the transmission’s compliance is not negligible in relation to the flexibility of the parallel kinematic structure. The approach considers the kinematic and dynamic coupling due to the parallel kinematic structure, the system’s mass distribution and the transmission’s stiffness. In the literature, several papers deal with the dynamic vibration analysis of parallel robots. Some of these also consider the transmissions between the motors and the actuated joints. However, these works mainly deal with the modal analysis of the robot’s mechanical structure or the displacement analysis of the transmission’s effects on the positioning error of the end-effector. The discussion of the proposed approach takes into consideration a linear delta robot. The results show that the system’s natural frequencies and the directions of the end-effector’s modal displacements strongly depend on its position in the working space.

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