A Design of Experiment Using Computation Fluid Dynamics for Spool-Type Hydraulic Valves

2000 ◽  
Author(s):  
Ronald H. Miller ◽  
Gary S. Strumolo ◽  
Carlos Leon
Keyword(s):  
Fluid Dynamics ◽  
Low Cost ◽  
Analytical Techniques ◽  
Global Market ◽  
Market Place ◽  
Performance Improvements ◽  
Control Factors ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
Multivariate Systems

Abstract In order to compete successfully in the global market place, manufactures must have the ability to produce high-quality, low-cost products that fully satisfy the customer’s needs. Many analytical techniques have been adopted by these manufactures aimed at improving customer and engineering quality. Nonlinear multivariate systems, however, complicate this process making the determination of controlling factors difficult. Often times, improvements in one area of the process or product compromises the performance in other areas. The Design of Experiments (DOE), pioneered by Taguchi, represents a powerful statistical method to help better understand nonlinear systems with the aim to improve quality and performance in engineering. A DOE using Computational Fluid Dynamics (CFD) is developed to better understand the influences of flow forces on valve design and performance. Geometric control factors for the spool valve are determined, enabling optimization and performance improvements.

scholarly journals An investigation into contracted loaded tip propellers using computational fluid dynamics (CFD)

2018 ◽  
Author(s):  
N R J Williams
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Test Data ◽  
Experimental Test ◽  
Performance Improvements ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
Cfd Method ◽  
Developed Pressure

This paper investigates the potential performance improvements of adding contracted loaded tips to propellers. A Wageningen B5-75 Series propeller has been simulated and verified against published experimental test data. Contracted tips have then been added to a Wageningen propeller and the modified propeller then simulated. A CFD method and model has been developed. Pressure, velocity and vector plots have all been analysed detailing the mechanism behind the contracted tips. Limitations behind this method have been explored and explained, and recommendations for further studies made. The development of a database of propeller characteristics and performance chart data to allow quick evaluation of designs has also been proposed. 

scholarly journals Biomagnetic Monitoring vs. CFD Modeling: A Real Case Study of Near-Source Depositions of Traffic-Related Particulate Matter along a Motorway

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1285
Author(s):  
Sarah Letaïef ◽  
Pierre Camps ◽  
Thierry Poidras ◽  
Patrick Nicol ◽  
Delphine Bosch ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particulate Matter ◽  
Cfd Simulation ◽  
Low Cost ◽  
Precast Concrete ◽  
Cfd Modeling ◽  
Concrete Wall ◽  
Fluorescence Measurements ◽  
Computational Fluid Dynamics Cfd

A test site located along a 12-lane motorway east of Montpellier, France, is used to evaluate the potential of biomagnetic monitoring on traffic-related particulate matter (PM) to parametrize a computational fluid dynamics (CFD) simulation of the local airflow. Two configurations were established on the site with three vegetated flat-top earth berms of a basic design, and a fourth one was located windward to the traffic roofed with a 4-m-high precast concrete wall. As a first step, PM deposition simultaneously on plant leaves, on low-cost passive artificial filters, and on soils was estimated from proxies supplied by magnetic and X-ray fluorescence measurements on both sides of the motorway. These latter revealed that traffic-related pollutants are present on soils samples highlighted with a clear fingerprint of combustion residues, and wears of breaks, vehicles, and highway equipment. Maximum PM accumulations were detected in the lee of the berm–wall combination, while no significant deposition was observed on both sides of the flat-top earth berms. These results are in line with measurements from PM µ-sensors operated by the regional state-approved air quality agency. Finally, we compared the experimental measurements with the outcomes of a computational fluid dynamics (CFD) modeling based on the Reynolds-Averaged Navier–Stokes (RANS) equations that consider the traffic-induced momentum and turbulence. The CFD modeling matches the experimental results by predicting a recirculated flow in the near wake of the berm–wall combination that enhances the PM concentration, whereas the flat-top berm geometry does not alter the pollutants’ transport and indeed contributes to their atmospheric dispersion.

P-93: Process and Performance Improvements for a Simple Low-Cost Multi-Domain Vertical-Alignment LCD

2005 ◽  
Vol 36 (1) ◽  
pp. 646 ◽  
Author(s):  
Hiap L. Ong ◽  
Ngwe Cheong ◽  
Jason Lo ◽  
Marty Metras ◽  
Ollie Woodard ◽  
...  
Keyword(s):  
Low Cost ◽  
Vertical Alignment ◽  
Performance Improvements ◽  
And Performance

Numerical Simulation Flow and Temperature Fields of Fiber Air Dispersion System

2015 ◽  
Vol 671 ◽  
pp. 242-247
Author(s):  
Meng Zhang ◽  
Xiao Hong Zhou
Keyword(s):  
Fluid Dynamics ◽  
Indoor Air ◽  
Low Cost ◽  
Temperature Fields ◽  
Experiment Data ◽  
Evaluation Standard ◽  
Dispersion System ◽  
Air Dispersion ◽  
Computational Fluid Dynamics Cfd ◽  
Air Diffusion

Fiber air dispersion system (FADS) is an advanced flexible ventilation terminal in ventilated areas. Its benefits are numerous, which are air diffusion without feeling, anti-condensation, easy cleaning and low cost etc. The technology of computational fluid dynamics (CFD) was used in this paper. At first, a physical model of the environment conditioned by FADS was built. Then, the both field of temperature and flow in the environment was simulated. The boundary conditions and parameters was measured and calculated. Finally, the numerical results were verified by comparing with the experiment data to confirm the reliability of the model. Meanwhile, by using the indoor air evaluation standard, FADS was confirmed to provide a more comfortable environment and better air quality.

scholarly journals Advancement of Turbine Aerodynamic Design Techniques

1993 ◽  
Author(s):  
Lisa W. Griffin ◽  
Frank W. Huber
Keyword(s):  
Fluid Dynamics ◽  
State Of The Art ◽  
Cfd Analysis ◽  
Aerodynamic Design ◽  
Turbine Efficiency ◽  
Component Design ◽  
Pump Stage ◽  
Computational Fluid Dynamics Cfd ◽  
The Government ◽  
And Performance

The Consortium for Computational Fluid Dynamics (CFD) Application in Propulsion Technology has been created at NASA/MSFC. Its purpose is to advance the state-of-the-art of CFD technology, to validate CFD codes and models, and to demonstrate the benefits attainable through the application of CFD in component design. Three teams are currently active within the Consortium: (1) the Turbine Technology Team, (2) the Pump Stage Technology Team, and (3) the Combustion Devices Technology Team. The goals, dynamics, and activities of the Turbine Team are the subjects of this paper. The Consortium is managed by NASA. The Turbine Team is co-coordinated by a NASA representative from the CFD area and an industry (Pratt & Whitney) representative from the area of turbine aerodynamic design. Membership of the Turbine Team includes experts in design, analysis, and testing from the government, industry, and academia. Each member brings a unique perspective, expertise, and experience to bear on the team’s goals of improving turbine efficiency and robustness while reducing the amount of developmental testing. To this end, an advanced turbine concept has been developed within the team using CFD as an integral part of the design process. This concept employs unconventionally high turning blades and is predicted to provide cost and performance benefits over traditional designs. This concept will be tested in the MSFC Turbine Airflow Facility to verify the design and to provide a unique set of data for CFD code validation. Currently, the team is developing and analyzing methods to reduce secondary and tip losses to further enhance turbine efficiency. The team has also targeted volute development as an area that could benefit from detailed CFD analysis.

scholarly journals Low-cost scalable discretization, prediction, and feature selection for complex systems

2020 ◽  
Vol 6 (5) ◽  
pp. eaaw0961 ◽  
Author(s):  
S. Gerber ◽  
L. Pospisil ◽  
M. Navandar ◽  
I. Horenko
Keyword(s):  
Feature Selection ◽  
Complex Systems ◽  
Low Cost ◽  
Data Driven ◽  
Discrete Approximations ◽  
Modeling Tools ◽  
Performance Improvements ◽  
The Mean ◽  
And Performance ◽  
Prediction Problems

Finding reliable discrete approximations of complex systems is a key prerequisite when applying many of the most popular modeling tools. Common discretization approaches (e.g., the very popular K-means clustering) are crucially limited in terms of quality, parallelizability, and cost. We introduce a low-cost improved quality scalable probabilistic approximation (SPA) algorithm, allowing for simultaneous data-driven optimal discretization, feature selection, and prediction. We prove its optimality, parallel efficiency, and a linear scalability of iteration cost. Cross-validated applications of SPA to a range of large realistic data classification and prediction problems reveal marked cost and performance improvements. For example, SPA allows the data-driven next-day predictions of resimulated surface temperatures for Europe with the mean prediction error of 0.75°C on a common PC (being around 40% better in terms of errors and five to six orders of magnitude cheaper than with common computational instruments used by the weather services).

Computational fluid dynamics analysis of the effect of throat diameter on the fluid flow and performance of ejector

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammadreza Salehi ◽  
Nader Pourmahmoud ◽  
Amir Hassanzadeh ◽  
S. Hoseinzadeh ◽  
P.S. Heyns
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Mach Number ◽  
Content Type ◽  
Standard Code ◽  
Computational Fluid Dynamics Analysis ◽  
Fluent Software ◽  
Computational Fluid Dynamics Cfd ◽  
Throat Diameter ◽  
And Performance

Purpose Using the computational fluid dynamics (CFD) technique, this paper aims to investigate the influence of key parameters such as throat diameter; the suction ratio on the flow field behaviors such as Mach number; pressure; and temperature. Design/methodology/approach To investigate the effect of throat diameter, it is simulated for 4, 6, 8 and 10 mm as throat diameters. The governing equations have been solved by standard code of Fluent Software together with a compressible 2 D symmetric and turbulence model with the standard k–ε model. First, the influence of the throat diameter is investigated by keeping the inlet mass flow constant. Findings The results show that a place of shock wave creation is changed by changing the throat diameter. The obtained results illustrate that the maximum amount of Mach number is dependent on the throat diameter. It is obtained from the results that for smaller throats higher Mach numbers can be obtained. Therefore, for mixing purposes smaller throats and for exhausting bigger throats seems to be appropriate. Originality/value The obtained numerical results are compared to the existing experimental ones which show good agreement.

scholarly journals Transformational Leadership: Implications for Organizational Competitive Advantage

2014 ◽  
Vol 4 (1) ◽  
pp. 276
Author(s):  
Kelechi John Ekuma
Keyword(s):  
Transformational Leadership ◽  
Competitive Advantage ◽  
Leadership Style ◽  
Global Market ◽  
Organisational Performance ◽  
Market Place ◽  
Leadership Theories ◽  
Organisational Effectiveness ◽  
Improved Performance ◽  
And Performance

There is a growing consensus among scholars and practitioners alike that maximising the potentials of human resources is central to organisational effectiveness and improved performance in the 21st century global market place of intense competition. It has also been suggested that the ways in which organisational leaders manage people can remarkably influence company performances and competitiveness. Despite this realisation however, scholars, managers and practitioners alike disagree on the most appropriate approach to organisational leadership. Indeed, there is an on-going debate about the leadership style that yields the best results for organisations in contemporary times. And whilst the debates rage, an increasingly dominant discourse is that transformational leadership is central to organisational effectiveness and gaining of competitive advantage. This notwithstanding, the most fundamental issue remains how to understand how transformational leadership practices impact on performance in practical terms. Consequently, producing an unequivocal response to the question ‘what does transformational leadership really contribute to organisational performance?’ has remained elusive. It is against this backdrop, that this article critically evaluates the concept of Transformational Leadership (henceforth TL), with a view of highlighting its contributions to organisational effectiveness and performance. Synthesising organisational and leadership theories and integrating literatures in organisational development and HR, the paper argues that there are evidences to suggest that there are clear linkages between TL, organisational effectiveness and improved performance. The paper further contends that emotional intelligence is key to the operationalization of TL and concludes that the greatest challenge remains how to quantify the contributions of TL in practical terms.

Analyses of the Compressor Performance Impacts of Centrifugal Compressor Scroll Deformation Due to Installation

2010 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Local Deformation ◽  
Discharge Pipe ◽  
Gas Compression ◽  
Study Results ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance ◽  
And Performance

Centrifugal compressors have widely applications in industrial gas compression processes. Limitations of installation and compressor package always request to modify the compressor geometry to fit certain constrains. Very often, the modifications of the scroll were performed to meet the space constrains. To meet the installation and package requirements, we always modify the scroll and discharge pipe of the compressors. In this study, an original designed scroll and a modified scroll were analyzed by using the Computational Fluid Dynamics (CFD). The study is focused on the performance impacts of the scroll local deformation due to installation constrains. The CFD showed favorable agreements with experiments for original scroll. The detailed flow characters and performance impacts were discussed and results showed that current modifications of the scroll did not have significant impacts to the compressor performance. The study results can be used as a basic guidance for a compressor manufactures.

Effects of Impeller Squealer Tip on Centrifugal Compressor Performance

2016 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Lorenzo Toni ◽  
Dante Tommaso Rubino
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Flow ◽  
Tip Clearance ◽  
Flow Coefficient ◽  
Performance Improvements ◽  
Positive Effects ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance ◽  
Load Conditions

This paper summarizes the main results sorted out from a Design of Experiment (DoE) based on a validated Computational Fluid Dynamics (CFD). Several tip recessed geometries applied to an unshrouded impeller were considered in conjunction with two tip clearance levels. The computations show that recessed tip geometries have positive effects when considering high flow coefficient values while in part-load conditions the gain is reduced. Starting from the results obtained when studying tip cavities, a single rim tip squealer geometry was then analysed: the proposed geometry leads to performance improvements for all the tested conditions considered in this work.

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