CFD Calculation of Sinkage and Trim

2000 ◽  
Vol 44 (01) ◽  
pp. 59-82
Author(s):  
Anil K. Subramani ◽  
Eric G. Paterson ◽  
Fred Stern
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Boundary Layers ◽  
Quantitative Agreement ◽  
Wave Profile ◽  
Wave Fields ◽  
Surface Ship ◽  
Sinkage And Trim ◽  
Computational Fluid Dynamics Cfd

A computational fluid dynamics (CFD) code for surface-ship boundary layers, wakes, and wave fields is extended by incorporating into it the capability of predicting sinkage and trim. The method is described and results are presented for the naval combatant FF1052 and the Series 60, Cg = 0.6 parent hull. Resistance, sinkage and trim, and wave profile on the hull are compared between the calculations and the experimental data. The trends in the data are predicted correctly and there is also good quantitative agreement overall between the calculations and the data.

scholarly journals Modelling of working processes of non-contact oil free vacuum pumps by computational fluid dynamics (CFD) methods

2021 ◽  
Vol 2059 (1) ◽  
pp. 012003
Author(s):  
A Burmistrov ◽  
A Raykov ◽  
S Salikeev ◽  
E Kapustin
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Mathematical Models ◽  
Cfd Models ◽  
Ansys Cfx ◽  
Sst Turbulence Model ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamic Meshing ◽  
Comparison With Experimental Data

Abstract Numerical mathematical models of non-contact oil free scroll, Roots and screw vacuum pumps are developed. Modelling was carried out with the help of software CFD ANSYS-CFX and program TwinMesh for dynamic meshing. Pumping characteristics of non-contact pumps in viscous flow with the help of SST-turbulence model were calculated for varying rotors profiles, clearances, and rotating speeds. Comparison with experimental data verified adequacy of developed CFD models.

Computational Fluid Dynamics Techniques for Flows in Lapple Cyclone Separator

2005 ◽  
Vol 498-499 ◽  
pp. 179-185
Author(s):  
A.F. Lacerda ◽  
Luiz Gustavo Martins Vieira ◽  
A.M. Nascimento ◽  
S.D. Nascimento ◽  
João Jorge Ribeiro Damasceno ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Turbulent Flow ◽  
Reynolds Stress ◽  
Cyclone Separator ◽  
Two Dimensional ◽  
Stress Components ◽  
Computational Fluid Dynamics Cfd

A two-dimensional fluidynamics model for turbulent flow of gas in cyclones is used to evaluate the importance of the anisotropic of the Reynolds stress components. This study presents consisted in to simulate through computational fluid dynamics (CFD) package the operation of the Lapple cyclone. Yields of velocity obtained starting from a model anisotropic of the Reynolds stress are compared with experimental data of the literature, as form of validating the results obtained through the use of the Computational fluid dynamics (Fluent). The experimental data of the axial and swirl velocities validate numeric results obtained by the model.

Uncertainty Assessment for Towing Tank Tests With Example for Surface Combatant DTMB Model 5415

2005 ◽  
Vol 49 (01) ◽  
pp. 55-68 ◽  
Author(s):  
Joe Longo ◽  
Fred Stern
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Uncertainty Assessment ◽  
Wave Profile ◽  
Assessment Methodology ◽  
Towing Tank ◽  
Measurement Systems ◽  
Sinkage And Trim ◽  
Surface Combatant ◽  
Wave Elevations

Uncertainty assessment methodology, procedures, and results are presented for most typical towing tank tests using a 3.048 m geosym of naval combatant DTMB model 5415, which is an established benchmark for computational fluid dynamics validation. The tests include resistance, sinkage and trim, wave profile, wave elevations, and nominal wake. The procedures are summarized and follow International Towing Tank Conference Quality Manual Procedures. The facility and measurement systems are briefly described, and detailed uncertainty assessment examples for each test are provided with descriptions of bias and precision limits and total uncertainties.

A Study of Aerodynamics Force Evaluation of Horizontal Axis Wind Turbine (HAWT) Blade Using 2D and 3D Comparison

2015 ◽  
Author(s):  
Nazia Binte Munir ◽  
Kyoungsoo Lee ◽  
Ziaul Huque ◽  
Raghava R. Kommalapati
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Blade Surface ◽  
Aerodynamic Forces ◽  
Horizontal Axis Wind Turbine ◽  
Computational Fluid Dynamics Cfd ◽  
Experimental Values ◽  
Nrel Phase Vi

The main purpose of the paper is to use Computational Fluid Dynamics (CFD) in 3-D analysis of aerodynamic forces of a Horizontal Axis Wind Turbine (HAWT) blade and compare the 3-D results with the 2-D experimental results. The National Renewable Energy Laboratory (NREL) Phase VI wind blade profile is used as a model for the analysis. The results are compared with the experimental data obtained by NREL at NASA Ames Research Center for the NREL Phase VI wind turbine blade. The aerodynamic forces are evaluated using 3-D Computational Fluid Dynamics (CFD) simulation. The commercial ANSYS CFX and parameterized 3-D CAD model of NREL Phase VI are used for the analysis. The Shear Stress Transport (SST) Gamma-Theta turbulence model and 0-degree yaw angle condition are adopted for CFD analysis. For the case study seven varying wind speeds (5 m/s, 7 m/s, 10 m/s, 13 m/s, 15 m/s, 20 m/s, 25 m/s) with constant blade rotational speed (72 rpm) are considered. To evaluate the 3-D aerodynamic effect sectional pressure coefficient (Cp) and integrated forces about primary axis such as normal, tangential, thrust and torque are evaluated for each of the seven wind speed cases and compared with the NREL experimental values. The numerical difference of values on wind blade surface between this study and 3-D results of NREL wind tunnel test are found negligible. The paper represents an important comparison between the 3-D lift & drag coefficient with the NREL 2-D experimental data. The results shows that though the current study is in good agreement with NREL 3-D experimental values there is large deviation between the NREL 2-D experimental data and current 3-D study which suggests that in case of 3-D analysis of aerodynamic force of blade surface it is better to use NREL 3-D values instead of 2-D experimental values.

Detailed Bow-Flow Data and CFD for a Series 60 CB = 0.6 Ship Model for Froude Number 0.316

1996 ◽  
Vol 40 (03) ◽  
pp. 193-199
Author(s):  
F. Stern ◽  
J. Longo ◽  
Z. J. Zhang ◽  
A. K. Subramani
Keyword(s):  
Thin Film ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Froude Number ◽  
Wave Profile ◽  
Flow Data ◽  
The Real ◽  
Ship Model ◽  
Wave Elevation ◽  
Computational Fluid Dynamics Cfd

The bow flow of the Series 60 CB = 0.6 ship model is reinvestigated using both experiments and computational fluid dynamics (CFD). More detailed bow-flow data are obtained by taking measurements of the wave elevation with a point gauge very near the bow. In the CFD, the bow flow is resolved in more detail by using the real bow geometry instead of the simplified vertical zero-thickness bow used in previous studies, which requires a much finer grid in the bow region. The experiments and CFD are briefly described; results are presented; and discussions are made concerning comparisons of the new and old CFD solutions with the extended data regarding the wave profile and elevation at the bow, the thin film and beads (i.e. attached spray sheet and bow vortices), and the stagnation effects.

CFD Simulation and Computation of Pressure Loss of Resistance Muffler

2013 ◽  
Vol 694-697 ◽  
pp. 307-311
Author(s):  
Jia Wei Ren ◽  
Qin Yu Jiang ◽  
Zhen Wang
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Pressure Loss ◽  
Cfd Simulation ◽  
Internal Flow ◽  
Simulation Algorithm ◽  
Air Velocity ◽  
Loss Of Resistance ◽  
Computational Fluid Dynamics Cfd

Computational fluid dynamics (CFD) software was used to simulate the internal flow field of an example muffler, and compared the results with the experimental data, verifying the reliability of the simulation algorithm. On this basis, changed the example muffler structure, researched the pressure loss of muffler which was influenced by the insert duct, the position of the baffle and the inlet air velocity. The corresponding regularities have been obtained with the results of computations, which provide a basis for the design of the muffler.

Comparison of Particle-Wall Interaction Boundary Conditions in the Prediction of Cyclone Collection Efficiency in Computational Fluid Dynamics (CFD) Modeling

2010 ◽  
Vol 660-661 ◽  
pp. 158-163
Author(s):  
M.Ramirez Valverde ◽  
José Renato Coury ◽  
José Antônio Silveira Gonçalves
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Collection Efficiency ◽  
Cfd Modeling ◽  
Wall Boundary Conditions ◽  
Computational Fluid Dynamics Cfd ◽  
Wall Interaction

In recent years, many computational fluid dynamics (CFD) studies have appeared attempting to predict cyclone pressure drop and collection efficiency. While these studies have been able to predict pressure drop well, they have been only moderately successful in predicting collection efficiency. Part of the reason for this failure has been attributed to the relatively simple wall boundary conditions implemented in the commercially available CFD software, which are not capable of accurately describing the complex particle-wall interaction present in a cyclone. According, researches have proposed a number of different boundary conditions in order to improve the model performance. This work implemented the critical velocity boundary condition through a user defined function (UDF) in the Fluent software and compared its predictions both with experimental data and with the predictions obtained when using Fluent’s built-in boundary conditions. Experimental data was obtained from eight laboratory scale cyclones with varying geometric ratios. The CFD simulations were made using the software Fluent 6.3.26.

Validation of CFD Predictions of the Hull Resistance and the Wave System of a Catamaran

2012 ◽  
Author(s):  
Alexandre T. P. Alho
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Design Process ◽  
Scale Effects ◽  
Wave System ◽  
Computational Fluid Dynamics Cfd ◽  
Resistance Prediction ◽  
Low Costs

In response to the need for better designs in less time and at low costs, computational fluid dynamics (CFD) is becoming an integral part of the vessel’s design process. Recent studies have shown that CFD techniques can be used with relative success for the problem of ship resistance prediction. This paper reports on the simulation of the flow around a typical catamaran hull by means of CFD computations. The numerical model used in the simulations was developed in full scale with the experimental model in order to eliminate any source of scale effects. The paper presents a discussion on grid configuration and an analysis of the performance of the numerical model in describing the characteristics of the in-between hulls flow. The results obtained were validated against experimental data.

scholarly journals An Overview of Hybrid RANS–LES Models Developed for Industrial CFD

2021 ◽  
Vol 11 (6) ◽  
pp. 2459
Author(s):  
Florian Menter ◽  
Andreas Hüppe ◽  
Alexey Matyushenko ◽  
Dmitry Kolmogorov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Large Eddy Simulation ◽  
Boundary Layers ◽  
Shear Flows ◽  
Low Cost ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Computational Fluid Dynamics Cfd

An overview of scale-resolving simulation (SRS) methods used in ANSYS Computational Fluid Dynamics (CFD) software is provided. The main challenges, especially when computing boundary layers in large eddy simulation (LES) mode, will be discussed. The different strategies for handling wall-bound flows using combinations of RANS and LES models will be explained, along with some specific application examples. It will be demonstrated that the stress-blended eddy simulation (SBES) approach is optimal for applications with a mix of boundary layers and free shear flows due to its low cost and its ability to handle boundary layers in both RANS and wall-modeled LES (WMLES) modes.

Sign in / Sign up

Export Citation Format

Share Document