PERFORMANCE PREDICTION OF WIND PROPULSION SYSTEMS USING 3D CFD AND ROUTE SIMULATION

2019 ◽  
Author(s):  
A Persson ◽  
D.-Q. Li ◽  
F Olsson ◽  
S Werner ◽  
U Dhomé
Keyword(s):  
Performance Prediction ◽  
New Technology ◽  
Vortex Formation ◽  
Propulsion Systems ◽  
Cfd Simulations ◽  
Energy Saving Potential ◽  
Reasonable Cost ◽  
Accurate Performance ◽  
3D Effects ◽  
Ship Performance

Accurate performance prediction is necessary when designing/optimising wind propulsion systems (WPS). An independent, trustworthy prediction of the energy-saving potential is also needed to support the ship owner’s decision to invest in new technology. By using weather statistics along with a mathematical model of ship performance, route simulations can estimate the time and power required for transit of a route. Such simulations are commonly used today to optimise the design and operation of conventional ships. The introduction of WPS poses additional challenges for route simulations. WPS performance must be predicted at all points along the route, with wind of differing velocity and direction. The apparent wind will vary vertically (twist), due to the interaction between the ship velocity and the atmospheric boundary layer. Also, many proposed concepts use multiple WPS, introducing additional complexity, such as independent spin ratios/ sheeting angles. 3D CFD simulations capture the complex physics, including vortex formation and interaction effects, providing accurate performance prediction and an understanding of the flow. However, 3D CFD is costly, and it would not be possible to simulate all conditions at a reasonable cost. We present simplified approaches to modelling of WPS, using a limited number of CFD simulations, either in 2D or 3D, which are then extrapolated such that 3D effects are represented, and all conditions covered. The methodology is demonstrated on rotor sails and wing sails.

A Discussion on recent advances in heavy electrical plant - Superconducting machines - a new era for the electrical power industry

1973 ◽  
Vol 275 (1248) ◽  
pp. 77-84 ◽  
Keyword(s):  
New Technology ◽  
Electrical Power ◽  
Industrial Applications ◽  
Propulsion Systems ◽  
Successful Development ◽  
New Era ◽  
Marine Propulsion ◽  
Short Period ◽  
Under Construction ◽  
Changing Attitudes

This paper outlines the development of superconducting d.c. machines at I.R.D. where most of the work to date has been undertaken. Particular emphasis will be placed upon the industrial applications for these machines and the paper contains illustrations of the superconducting marine propulsion systems now under construction. The object of the presentation is to demonstrate that superconducting d.c. machines are now available for industrial application after a relatively short period of development. The paper also indicates the substantial advantages to be gained from the successful development of superconducting a.c. generators. The work which is necessary before these machines may be put into production will be discussed by consideration of the principal problem areas. Finally, conclusions are drawn on the present status of superconducting machines and the changing attitudes in industry towards this new technology.

scholarly journals Improved Performance Prediction of Marine Propeller: Numerical Investigation and Experimental Verification

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yue Tan ◽  
Jing Li ◽  
Yuan Li ◽  
Chunbao Liu
Keyword(s):  
Experimental Data ◽  
Performance Prediction ◽  
Outer Boundary ◽  
Tangential Velocity ◽  
Marine Propeller ◽  
Computational Performance ◽  
Accurate Performance ◽  
Improved Performance ◽  
Experimental Values ◽  
Good Agreement

An approach was presented to improve the performance prediction of marine propeller through computational fluid dynamics (CFD). After a series of computations were conducted, it was found that the passage in the former study was too narrow, resulting in the unnecessary radial outer boundary effects. Hence, in this study, a fatter passage model was employed to avoid unnecessary effects, in which the diameter was the same as the length from the propeller to the downstream outlet and the diameter was larger than the previous study. The diameter and length of the passage were 5D and 8D, respectively. The propeller DTMB P5168 was used to evaluate the fat passage model. During simulation, the classical RANS model (standard k-ε) and the Multiple Reference Frame (MRF) approach were employed after accounting for other factors. The computational performance results were compared with the experimental values, which showed that they were in good agreement. The maximum errors of Kt and Kq were less than 5% and 3% on different advance coefficients J except 1.51, respectively, and that of η was less than 2.62%. Hence the new model obtains more accurate performance prediction compared with published literatures. The circumferentially averaged velocity components were also compared with the experimental results. The axial and tangential velocity components were also in good agreement with the experimental data. Specifically, the errors of the axial and tangential velocity components were less than 3%, when the r/R was not less than 3.4. When the J value was larger, the variation trends of radial velocity were consistent with the experimental data. In conclusion, the fat passage model proposed here was applicable to obtain the highly accurate predicted results.

scholarly journals Technologies for mathematical and computer modeling to automate the process of operational states development for heat supply systems

2020 ◽  
Vol 209 ◽  
pp. 02026
Author(s):  
Zoya I. Shalaginova ◽  
Vyacheslav V. Tokarev ◽  
Oksana A. Grebneva ◽  
Aleksandr V. Lutsenko
Keyword(s):  
Heat Supply ◽  
New Technology ◽  
Object Oriented ◽  
Hierarchical Optimization ◽  
Energy Saving Potential ◽  
Methods Of Calculation ◽  
Pumping Stations ◽  
Large Systems ◽  
Supply Systems

This article proposes the new technology for development of operational states for HSS of arbitrary structure and dimension. Technology is based on multilevel modeling and a new method for adjustment calculation of thermal hydraulic states. It is implemented in the information and computer complex «ANGARA-HN». Technology includes checking the permissibility of states, calculating the throttling devices on the network and inputs of consumers’ buildings. It allows calculating large systems with intermediate stages of regulation, developing adjustment measures to improve the quality of heat supply and consumer provision, reducing circulation flow rates and pressure in networks. The development of modeling methods is carried out in the following directions: taking into account the new composition of equipment, including mixing pumping stations; development of nontraditional methods of calculation, such as object-oriented modeling; development of tasks of hierarchical optimization and identification of state parameters, as task of rising for model adequacy; development of task for finding of sectioning variants for multi-circuit heat network with several sources. The application of methodological and software developments makes it possible to obtain both an economic and a social effect by identifying and realizing of the energy saving potential, improving the quality and reliability.

scholarly journals Simulating the Effects of a Green Payment Program on the Diffusion Rate of a Conservation Technology

2004 ◽  
Vol 33 (1) ◽  
pp. 121-137 ◽  
Author(s):  
Kenneth A. Baerenklau
Keyword(s):  
Behavioral Change ◽  
Peer Group ◽  
New Technology ◽  
Cost Effective ◽  
Dairy Farmers ◽  
Prior Beliefs ◽  
Group Influence ◽  
Income Distributions ◽  
Reasonable Cost ◽  
Conservation Technology

The decision to adopt a potentially profitable but unfamiliar conservation technology is cast in a multi-period Bayesian framework. Specifically, dairy farmers who are both risk-averse and susceptible to peer group influence progressively learn about the true impact of adopting reduced phosphorus dairy diets on their income distributions as they repeatedly experiment with this new technology. Empirically calibrated simulations are used to examine the effects of a voluntary green payment program on the rate of technological diffusion. Results suggest that (a) green payments can accelerate learning and produce significant, permanent changes in behavior relatively quickly and for a reasonable cost; (b) shorter contracts offering larger incentives may be more cost-effective when learning plays an important role in behavioral change; and (c) unknown prior beliefs can reduce the efficacy of a green payment program, implying efforts to verify these priors or to ensure against them by increasing the payment level may be worthwhile.

Curtis Stage Nozzle/Rotor Aerodynamic Interaction and the Effect on Stage Performance

2006 ◽  
Vol 129 (3) ◽  
pp. 551-562 ◽  
Author(s):  
Stephen Rashid ◽  
Matthew Tremmel ◽  
John Waggott ◽  
Randall Moll
Keyword(s):  
Performance Prediction ◽  
Performance Testing ◽  
Cfd Modeling ◽  
Stage Design ◽  
Aerodynamic Interaction ◽  
Accurate Performance ◽  
Computational Fluid Dynamics Cfd ◽  
Stage Performance ◽  
Improved Performance ◽  
And Performance

Curtis, or velocity compounded, stages commonly don’t achieve the same accuracy of performance prediction expected of most other turbine stages. A review of Curtis stage design practices, field wear, and dirt patterns, in conjunction with performance testing and computational fluid dynamics (CFD) modeling, determined that the nozzle/rotor aerodynamic interaction is far more complex than typical design and performance calculations assume. Understanding this nozzle/rotor interaction is key to obtaining both improved performance, and a more accurate performance prediction. This paper discusses the nature of this interaction, and it’s implications to Curtis stage performance prediction.

Sign in / Sign up

Export Citation Format

Share Document