scholarly journals On the Selection of Optimal Propeller Diameter for a 120m Cargo Vessel

2018 ◽  
Author(s):  
Jennie Andersson ◽  
Robert Gustafsson ◽  
Arash Eslamdoost ◽  
Rickard E. Bensow
Keyword(s):  
Open Water ◽  
Operating Conditions ◽  
Series Data ◽  
Preliminary Design ◽  
Optimum Diameter ◽  
Viscous Losses ◽  
Computational Fluid Dynamics Cfd ◽  
Propulsion Unit ◽  
Hydrodynamic Effects ◽  
Selection Of

In the preliminary design of a propulsion unit the selection of propeller diameter is most commonly based on open water tests of systematic propeller series. The optimum diameter obtained from the propeller series data is however not considered to be representative for the operating conditions behind the ship, instead a slightly smaller diameter is often selected. We have used computational fluid dynamics (CFD) to study a 120m cargo vessel with an integrated rudder bulb-propeller hubcap system and a 4-bladed propeller series, to increase our understanding of the hydrodynamic effects influencing the optimum. The results indicate that a 3-4 % smaller diameter is optimal in behind conditions in relation to open water conditions at the same scale factor. The reason is that smaller, higher loaded propellers perform better together with a rudder system. This requires that the gain in transverse kinetic energy losses thanks to the rudder overcomes the increase in viscous losses in the complete propulsion system.

scholarly journals On the Selection of Optimal Propeller Diameter for a 120-m Cargo Vessel

2020 ◽  
pp. 1-14
Author(s):  
Jennie Andersson ◽  
Robert Gustafsson ◽  
Arash Eslamdoost ◽  
Rickard E. Bensow
Keyword(s):  
Open Water ◽  
Operating Conditions ◽  
Series Data ◽  
Energy Losses ◽  
Preliminary Design ◽  
Optimum Diameter ◽  
Viscous Losses ◽  
Propulsion Unit ◽  
Hydrodynamic Effects ◽  
Selection Of

In the preliminary design of a propulsion unit, the selection of propeller diameter is most commonly based on open water tests of systematic propeller series. The optimum diameter obtained from the propeller series data is, however, not considered to be representative for the operating conditions behind the ship, instead a slightly smaller diameter is often selected. We have used computational fluid dynamics to study a 120-m cargo vessel with an integrated rudder bulb-propeller hubcap system and a four-bladed propeller series, to increase our understanding of the hydrodynamic effects influencing the optimum. The results indicate that a 3-4% smaller diameter is optimal in behind conditions in relation to open water conditions at the same scale factor. The reason is that smaller, higher loaded propellers perform better together with a rudder system. This requires that the gain in transverse kinetic energy losses thanks to the rudder overcomes the increase in viscous losses in the complete propulsion system.

scholarly journals Material Origins of Accelerated Operational Wear of RD-33 Engine Blades

2020 ◽  
Author(s):  
Adam Kozakiewicz ◽  
Stanislaw Jóźwiak ◽  
Przemysław Jóźwiak ◽  
Stanisław Kachel
Keyword(s):  
Chemical Composition ◽  
Construction Material ◽  
Operating Conditions ◽  
Design Stage ◽  
Strength Analysis ◽  
Jet Engine ◽  
Emergency Situations ◽  
Low Pressure Turbine ◽  
Propulsion Unit ◽  
Selection Of

The structural and strength analysis of the material used to construct such an important engine element as the turbine is of great significance, both at the design stage as well as during tests and expertises related to emergency situations. Bearing in mind the conditions above mentioned, the paper presents the results of research on the chemical composition, morphology and phased structure of the metallic construction material used to produce the blades of the high and low pressure turbine of the RD-33 jet engine, which is the propulsion unit of the MiG-29 aircraft. The data obtained as a result of the material tests of the blades allowed, on the basis of the analysis of chemical composition and phased structure, to determine the grade of the alloy used to construct the tested elements of the jet engine turbine. The structural stability of the material was found to be lower in comparison with engine operating conditions, which manifested itself as a clear decrease in the resistance properties of the blade material. The results obtained can be used as a basis for analyzing the life span of an object or a selection of material replacements, which enable to produce the analyzed engine element.

scholarly journals Material Origins of the Accelerated Operational Wear of RD-33 Engine Blades

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 336
Author(s):  
Adam Kozakiewicz ◽  
Stanisław Jóźwiak ◽  
Przemysław Jóźwiak ◽  
Stanisław Kachel
Keyword(s):  
Chemical Composition ◽  
Construction Material ◽  
Operating Conditions ◽  
Design Stage ◽  
Strength Analysis ◽  
Jet Engine ◽  
Emergency Situations ◽  
Materials Used ◽  
Propulsion Unit ◽  
Selection Of

The structural and strength analysis of the materials used to construct an important engine element such as the turbine is of great significance, at both the design stage and during tests and training relating to emergency situations. This paper presents the results of a study on the chemical composition, morphology, and phased structure of the metallic construction material used to produce the blades of the high- and low-pressure turbines of the RD-33 jet engine, which is the propulsion unit of the MiG-29 aircraft. On the basis of an analysis of the chemical composition and phased structure, the data obtained from tests of the blade material allowed the grade of the alloy used to construct the tested elements of the jet engine turbine to be determined. The structural stability of the material was found to be lower in comparison with the engine operating conditions, which was shown by a clear decrease in the resistance properties of the blade material. The results obtained may be used as a basis for analyzing the life span of an object or a selection of material replacements, which may enable the production of the analyzed engine element.

scholarly journals A New Approach for Centrifugal Impeller Preliminary Design and Aerothermal Analysis

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Fangyuan Lou ◽  
John C. Fabian ◽  
Nicole L. Key
Keyword(s):  
Sensitivity Study ◽  
Operating Conditions ◽  
New Method ◽  
Centrifugal Impeller ◽  
Preliminary Design ◽  
New Approach ◽  
Relative Diffusion ◽  
Wide Range ◽  
Effectiveness Parameter ◽  
Selection Of

This paper introduces a new approach for the preliminary design and aerothermal analysis of centrifugal impellers using a relative diffusion effectiveness parameter. The relative diffusion effectiveness is defined as the ratio of the achieved diffusion to the maximum available diffusion in an impeller. It represents the quality of the relative diffusion process in an impeller. This parameter is used to evaluate impeller performance by correlating the relative diffusion effectiveness with the impeller isentropic efficiency using the experimental data acquired on a single-stage centrifugal compressor (SSCC). By including slip, which is appropriate considering it is an inviscid effect that should be included in the determination of maximum available diffusion in the impeller, a linear correlation between impeller efficiency and relative diffusion effectiveness resulted for all operating conditions. Additionally, a new method for impeller preliminary design was introduced using the relative diffusion effectiveness parameter, in which the optimal design is selected to maximize relative diffusion effectiveness. While traditional preliminary design methods are based on empirical loss models or empirical knowledge for selection of diffusion factor (DF) in the impeller, the new method does not require any such models, and it also provides an analytical approach for the selection of DF that gives optimal impeller performance. Validation of the method was performed using three classic impeller designs available in the open literature, and very good agreement was achieved. Furthermore, a sensitivity study shows that the method is robust in that the resulting flow angles at the impeller inlet and exit are insensitive to a wide range of blockage factors and various slip models.

Adaptation Application to Engine Modelling

2007 ◽  
Author(s):  
Jude Iyinbor
Keyword(s):  
Measurement Data ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Adaptation Process ◽  
Design Point ◽  
Component Map ◽  
Important Measurement ◽  
Unknown Component ◽  
Selection Of

The optimisation of engine performance by predictive means can help save cost and reduce environmental pollution. This can be achieved by developing a performance model which depicts the operating conditions of a given engine. Such models can also be used for diagnostic and prognostic purposes. Creating such models requires a method that can cope with the lack of component parameters and some important measurement data. This kind of method is said to be adaptive since it predicts unknown component parameters that match available target measurement data. In this paper an industrial aeroderivative gas turbine has been modelled at design and off-design points using an adaptation approach. At design point, a sensitivity analysis has been used to evaluate the relationships between the available target performance parameters and the unknown component parameters. This ensured the proper selection of parameters for the adaptation process which led to a minimisation of the adaptation error and a comprehensive prediction of the unknown component and available target parameters. At off-design point, the adaptation process predicted component map scaling factors necessary to match available off-design point performance data.

Study of Self-Propelled Pufferfish Driven by Multiple Fins: A Comparison Between Rigid and Deformable Fins

2017 ◽  
Author(s):  
Ruoxin Li ◽  
Qing Xiao ◽  
Lijun Li ◽  
Hao Liu
Keyword(s):  
Underlying Mechanism ◽  
Operating Conditions ◽  
The Self ◽  
Fish Swimming ◽  
Propulsion Efficiency ◽  
Live Fish ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Body ◽  
Better Than

In this work, we numerically studied the steady swimming of a pufferfish driven by the undulating motion of its dorsal, anal and caudal fins. The simulations are based on experimentally measured kinematics. To model the self-propelled fish swimming, a Computational Fluid Dynamics (CFD) tool was coupled with a Multi-Body-Dynamics (MBD) technique. It is widely accepted that deformable/flexible or undulating fins are better than rigid fins in terms of propulsion efficiency. To elucidate the underlying mechanism, we established an undulating fins model based on the kinematics of live fish, and conducted a simulation under the same operating conditions as rigid fins. The results presented here agree with this view by showing that the contribution of undulating fins to propulsion efficiency is significantly larger than that of rigid fins.

scholarly journals The Business Service Sector in India, Ireland and Poland. A Comparative Analysis

2019 ◽  
Vol 22 (2) ◽  
pp. 159-172
Author(s):  
Arkadiusz Mroczek
Keyword(s):  
Comparative Analysis ◽  
Service Sector ◽  
Operating Conditions ◽  
Business Service ◽  
Literature Study ◽  
Location Factors ◽  
Current Growth ◽  
Characteristic Features ◽  
Selection Of ◽  
Made In

The fast growth of the service sector is one of the characteristic features of the contemporary economy. Amongst other CEE countries, Poland is one of the emerging locations for this sector. The aim of the paper is to examine and compare the business service sector in India, Ireland and Poland. Both India and Ireland are exceptional locations for this industry, so comparing the state and operating conditions in Poland with those countries can be insightful. A literature study is used to determine the motives of companies undertaking offshore investments, upon which a selection of location factors is made. In the empirical part, those factors are analyzed in a descriptive way. This allows us to draw conclusions concerning this sector in Poland. This country, to some extent, possesses selected positive features of both India and Ireland, which explains the current growth of the sector.

scholarly journals Catheter placement selection for convection-enhanced delivery of therapeutic agents to brain tumors

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1415
Author(s):  
Lisa H. Antoine ◽  
Roy P. Koomullil ◽  
Timothy M. Wick ◽  
Louis B. Nabors ◽  
Ahmed K. Abdel Aal ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Tumor Volume ◽  
Therapeutic Agents ◽  
Catheter Placement ◽  
Volume Distribution ◽  
Convection Enhanced Delivery ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Magnetic Resonance Imaging Mri ◽  
Selection Of

Background: Convection-enhanced delivery (CED) of therapeutic agents to brain tumors allows clinicians to bypass the blood-brain barrier (BBB) to infuse virus therapy, biological, or chemotherapy directly into a brain tumor through convection. However, the effectiveness of infusions via CED may depend on catheter placement. Methods: This study used diffusion maps from magnetic resonance imaging (MRI) of human brain tumors and computational fluid dynamics (CFD) simulations to assess therapy volume distribution percentages based on catheter placement locations. Results: The primary outcome showed differences in volume distribution based on the catheter placement location. Total tumor volume filled ranged from 144.40 mm3 to 317.98 mm3. Percent filled of tumor volume ranged from 2.87% to 6.32%. Conclusions: The selection of the location for catheter placement using the region with the highest volume filled may provide optimal therapeutic effect.  The researchers conclude that CFD may provide guidance for catheter placement in CED of therapeutic agents.

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