scholarly journals CFD results on hydrodynamic performances of a marine propeller

2019 ◽  
Vol 19 (3) ◽  
pp. 345-447
Author(s):  
Luong Ngoc Loi ◽  
Nguyen Chi Cong ◽  
Ngo Van He
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pitch Angle ◽  
Container Ship ◽  
Marine Propeller ◽  
Ansys Fluent ◽  
Characteristic Curves ◽  
Computational Fluid Dynamics Cfd ◽  
Ship Propeller ◽  
Blade Pitch Angle

In this work, the commercial Computational Fluid Dynamics (CFD), ANSYS-Fluent V.14.5 has been used to illustrate the effects of rudder and blade pitch on hydrodynamic performances of a propeller. At first, the characteristic curves of a container ship propeller are computed. Then, effects of rudder on hydrodynamic performances of the propeller in the both cases of the propeller with and without rudder have been investigated. The relationships between the blade pitch angle and the hydrodynamic performances of the selected referent propeller in this work having designed conditions as diameter of 3.65 m; speed of 200 rpm; average pitch of 2.459 m and the boss ratio of 0.1730. Using CFD, the characteristic curves of the marine propeller, pressure distribution, velocity distribution around propeller and the efficiency of the propeller have been shown. From the obtained results, the effects of rudder and blade pitch angle on hydrodynamic performances of the propeller have been evaluated.

Analysis and Simulation of Inner Flow Condition of a Novel Rotary on/off Valve

2012 ◽  
Vol 220-223 ◽  
pp. 1698-1702
Author(s):  
Jian Chen ◽  
Zhu Ming Su ◽  
Qi Zhou ◽  
Jian Ping Shu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Condition ◽  
High Speed ◽  
Ansys Fluent ◽  
Revolution Speed ◽  
Pressure Profiles ◽  
Open Case ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

A novel hydraulic rotary high speed on/off valve is investigated. The function of the outlet turbine and the effect on revolution speed of valve spool are analyzed. The inner fluid flow condition under full open case of the on/off valve is simulated using computational fluid dynamics(CFD) method based on Ansys/Fluent and velocity and pressure profiles of fluid inside valve are obtained. Suggestions on optimizing the geometry of valve to decrease transition losses are given.

scholarly journals Simulasi Pengaruh Radius Channel Garam dan Temperatur Terhadap Distribusi Temperatur Pada Teras Molten Salt Breeder Reactor

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Elin Yusibani ◽  
Hidayatun Nisa ◽  
Rajibussalim Rajibussalim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Molten Salt ◽  
Ansys Fluent ◽  
Computational Fluid Dynamics Cfd

Penelitian ini bertujuan untuk mensimulasikan distribusi temperatur dengan variasi radius channel garam dan temperatur masukan pada teras Molten Salt Breeder Reactor (MSBR). Computational Fluid Dynamics (CFD) dengan perangkat lunak Ansys Fluent digunakan pada simulasi ini untuk sebuah sel moderator. Variasi radius channel garam adalah 0,0108 m; 0,0208; dan 0,0308 m dengan panjang moderator 3,96 m. Variasi temperatur masukan adalah 809 K, 839 K, 859 K, dan 909 K. Hasil simulasi pada variasi radius menunjukkan bahwa dengan pertambahan sebesar 0,01 m memberikan kenaikan suhu sebesar 8 - 23 K pada temperatur masukan konstan. Perubahan terhadap temperatur masukan, diperoleh kenaikan temperatur keluaran antara 1 - 10 K, pada radius channel garam yang konstan. Dengan demikian dapat disimpulkan bahwa distribusi temperatur dalam teras MSBR akan meningkat jika radius channel garam diperkecil atau temperatur masukan dinaikkan.

scholarly journals Trim Influence on Kriso Container Ship (KCS): An Experimental and Numerical Study

2017 ◽  
Author(s):  
Emil Shivachev ◽  
Mahdi Khorasanchi ◽  
Alexander H. Day
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Study ◽  
Computational Cost ◽  
Breaking Waves ◽  
Computational Techniques ◽  
Container Ship ◽  
Towing Tank ◽  
Operational Life ◽  
Computational Fluid Dynamics Cfd

There has been a lot of interest in trim optimisation to reduce fuel consumption and emissions of ships. Many existing ships are designed for a single operational condition with the aim of producing low resistance at their design speed and draft with an even keel. Given that a ship will often sail outside this condition over its operational life and moreover some vessels such as LNG carriers return in ballast condition in one leg, the effect of trim on ships resistance will be significant. Ship trim optimization analysis has traditionally been done through towing tank testing. Computational techniques have become increasingly popular for design and optimization applications in all engineering disciplines. Computational Fluid Dynamics (CFD), is the fastest developing area in marine fluid dynamics as an alternative to model tests. High fidelity CFD methods are capable of modelling breaking waves which is especially crucial for trim optimisation studies where the bulbous bow partially emerges or the transom stern partially immerses. This paper presents a trim optimization study on the Kriso Container Ship (KCS) using computational fluid dynamics (CFD) in conjunction with towing tank tests. A series of resistance tests for various trim angles and speeds were conducted at 1:75 scale at design draft. CFD computations were carried out for the same conditions with the hull both fixed and free to sink and trim. Dynamic sinkage and trim add to the computational cost and thus slow the optimisation process. The results obtained from CFD simulations were in good agreement with the experiments. After validating the applicability of the computational model, the same mesh, boundary conditions and solution techniques were used to obtain resistance values for different trim conditions at different Froude numbers. Both the fixed and free trim/sinkage models could predict the trend of resistance with variation of trim angles; however the fixed model failed to measure the absolute values as accurately as the free model. It was concluded that a fixed CFD model, although computationally faster and cheaper, can find the optimum trim angle but cannot predict the amount of savings with very high accuracy. Results concerning the performance of the vessel at different speeds and trim angles were analysed and optimum trim is suggested.

scholarly journals Comparison of computational fluid dynamics-based simulations and visualized seed trajectories in different seed tubes

2020 ◽  
Vol 44 (6) ◽  
pp. 599-611
Author(s):  
Arzu YAZGI ◽  
Vedat DEMİR ◽  
Adnan DEĞİRMENCİOĞLU
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Free Fall ◽  
Video Camera ◽  
Ansys Fluent ◽  
Release Point ◽  
Seed Spacing ◽  
Seed Distribution ◽  
Computational Fluid Dynamics Cfd ◽  
Distribution Uniformity

The objective of this study was to compare computational fluid dynamics (CFD)-based simulations and visualized seed trajectories in different seed tubes that can provide seed incorporation into the soil with enhanced seed spacing. The other objective was to determine the relation between the seed trajectories and peripheral speed of the vacuum disk. In order to meet the first objective, 2 different seeds (corn and cotton) and artificial spherical material (Ø10 mm) were tested under laboratory conditions. The seeds and artificial material were released by free fall into the semitransparent seed tubes (seed tubes A and B) from different release points, and their trajectories were recorded using a video camera. For the second objective, corn seeds were used and released from a vacuum-type metering unit equipped with a semitransparent seed tube (seed tube A) at 3 different peripheral speeds of the vacuum disk, as a function of 3 forward speeds of the seeder. For both objectives, the seed tubes were modeled and release of the seeds into the seed tubes was simulated and analyzed using ANSYS Fluent for CFD. The results obtained from the captured video and simulations were compared. As a result of the comparisons, it was found that the seed release point was an effective parameter on both the seed trajectory and seed spacing, since seed bouncing and skating in the seed tube, based on the release point, may occur. The results also showed that the lab tests and simulations were found to be very similar in terms of the seed trajectories and seed spacings. It is believed that this study, using CFD, will be an example and enable the development and design of new seed tubes in order to obtain better seed distribution uniformity.

Modeling of High Temperature Gas Flow 3D Distribution in BF Throat Based on the Computational Fluid Dynamics

2015 ◽  
Vol 19 (2) ◽  
pp. 269-276 ◽  
Author(s):  
Jian Qi An ◽  
◽  
Kai Peng ◽  
Wei Hua Cao ◽  
Min Wu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gas Flow ◽  
Numerical Solutions ◽  
Flow Distribution ◽  
Three Dimensions ◽  
Cfd Model ◽  
Ansys Fluent ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd

This paper aims at building a Computational Fluid Dynamics (CFD) model which can describe the gas flow three dimensions (3D) distribution in blast furnace (BF) throat. Firstly, the boundary conditions are obtained by rebuilding central gas flow shape in BF based on computer graphics. Secondly, the CFD model is built based on turbulent model by analyzing the features of gas flow. Finally, a method which can get the numerical solutions of the model is proposed by using CFD software ANSYS/FLUENT. The proposed model can reflect the changes of the gas flow distribution, and can help to guide the operation of furnace burdening and to ensure the BF stable and smooth production.

Optimization of a Combined Photovoltaic/Thermal Unit Using Computational Fluid Dynamics

2014 ◽  
Author(s):  
Andrew Roberts ◽  
Ming-Chia Lai ◽  
Chi-Yang Cheng
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Theoretical Model ◽  
Cfd Model ◽  
Ansys Fluent ◽  
Climate Conditions ◽  
Flow Energy ◽  
Computational Fluid Dynamics Cfd ◽  
Heat Transfer System ◽  
D Model

The goal of this project was to develop a model for a Combined Photovoltaic/Thermal (PV/T) unit to ease in the assessment of potential changes to the unit before fabrication of actual parts. This process reduces the time to assess changes in the system; once the initial model is created changes are relatively simple. It also reduces cost incurred for actual testing by certified labs and can simulate output variations in different climate conditions, site locations and times of year. A commercially available PV/T unit was chosen for analysis, which utilizes two water channels under the photovoltaic assembly instead of the conventional sheet-and-tube design to actively cool the solar cells while also collecting thermal energy that can be used for heating water or air via a heat transfer system. The project described in this paper modeled the PV/T unit in two ways: (1) as a one-dimensional theoretical model and (2) modeling the system in ANSYS FLUENT and simulating the fluid flow, energy and radiation models using computational fluid dynamics (CFD). The baseline CFD model was correlated to published Solar Rating and Certification Corporation (SRCC) test data for pressure drop and thermal performance to gage accuracy of the model. Through a literature search of past work on similar modules and systems, several potential improvements to the unit were identified and a detailed analysis was conducted by individually adding each to the theoretical model, then comparing them to the output of the baseline model. Combinations of improvements were evaluated as well and assessed based on output improvement, technical feasibility and expected cost. The accuracy of the 1-D model was compared to the CFD model to assess the benefits gained from the added complexity of using computational fluid dynamics.

scholarly journals Mixing Performance of Counter-Axial Flow Impeller using Computational Fluid Dynamics

2018 ◽  
Vol 8 (02) ◽  
Author(s):  
Ian Torotwa ◽  
Changying Ji
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Axial Flow ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Ansys Fluent ◽  
Rushton Turbine ◽  
Mixing Performance ◽  
Computational Fluid Dynamics Cfd

In this study, turbulent flow fields in a baffled vessel stirred by counter-axial flow impeller have been investigated in comparison to the Rushton turbine. The resultant turbulence was numerically predicted using computational fluid dynamics (CFD). Turbulence models were developed in ANSYS Fluent 18.1 solver using the Navier-Stokes equation with the standard k-ε turbulence model. The Multiple Reference Frame (MRF) approach was used to simulate the impeller action in the vertical and horizontal planes of the stirred fluid volume. Velocity profiles generated from the simulations were used to predict and compare the performance of the two designs. To validate the CFD model, the simulation results were compared with experimental results from existing work and a satisfactory agreement was established. It was concluded that the counter-axial flow impeller could provide better turbulence characteristics that would improve the quality of mixing systems.

scholarly journals CFD investigation of interaction effect between hull and accommodation on wind drag of a container ship in head wind

2021 ◽  
Vol 21 (1) ◽  
pp. 37-46
Author(s):  
He Ngo Van ◽  
Thuan Truong Van
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Interaction Effect ◽  
Reference Model ◽  
Interaction Effects ◽  
Aerodynamic Performance ◽  
Container Ship ◽  
Total Resistance ◽  
Aerodynamic Performances ◽  
Computational Fluid Dynamics Cfd

In this paper, we present a research on applying a commercial Computational Fluid Dynamics (CFD) code to determine interaction effect between hull and accommodation on wind drag of a container ship. For the high superstructure and large windward area ships such as container, wind drag acting on hull accounts for a large amount of total resistance. To clearly find aerodynamic performance and interaction effects on wind drag of a container ship, a full scale 1,200 TEU container has been used as a reference model. From results of comparison in the two computed cases of hull with and without accommodation, the interaction effects between hull and accommodation on aerodynamic performance and wind drag have been investigated. The targets of the paper has proposed a new solution to improve aerodynamic performances and reduce wind drag acting on the ship by reducing interaction effects between hull and accommodation.

Study on Inner Vortex in a Hydrocyclone through Numerical Simulation

2013 ◽  
Vol 788 ◽  
pp. 228-232
Author(s):  
Zhuo Lun Cen ◽  
Ji Gang Zhao ◽  
Ben Xian Shen
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Swirling Flow ◽  
Small Diameter ◽  
Ansys Fluent ◽  
Detailed Understanding ◽  
Inlet Velocity ◽  
Computational Fluid Dynamics Cfd

Hydrocyclones provide an economic and efficient process of separation in many industries, but there has been little detailed understanding of the strong swirling flow prevailing inside the device, especially the complex inner vortex. This work presented a computational fluid dynamics (CFD) simulation to predict and to evaluate the effects of inlet velocity and the diameter of overflow tube on the inner vortex. The calculation was carried out using commercial CFD code Ansys Fluent 14.0. The results obtained demonstrates both an overlarge inlet velocity and a too small diameter of overflow tube lead to a severe backmixing at the head of hydrocyclone, moreover the latter results in a disorder and unstructured inner vortex.

scholarly journals Hydraulic analysis of gate valve using computational fluid dynamics (CFD)

2020 ◽  
Vol 29 (3) ◽  
pp. 275-288
Author(s):  
Elvis Žic ◽  
Patrik Banko ◽  
Luka Lešnik
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Supply ◽  
Gate Valve ◽  
Extreme Values ◽  
Water Supply Systems ◽  
Ansys Fluent ◽  
Hydrodynamic Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Physical Quantities

As a very important element of most water supply systems, valves are exposed to the effects of strong hydrodynamic forces. When exposed to large physical quantities, the valve and piping can be damaged, which could endanger the performance of a water supply system. This is the main reason why it is necessary to foresee and determine the maximum values of velocity, pressure and other physical quantities that can occur in the system under certain conditions. Predicting extreme conditions allows us to correctly size the valve for the expected conditions to which the valve might be exposed, which is also the main objective of this paper. One of the methods for predicting and determining extreme values on a valve is to perform a simulation with computational fluid dynamics (CFD). This is exactly the method used in the preparation of this paper with the aim of gaining insight into the physical magnitudes for models of gate valves positioned inside a pipe under characteristic degrees of valve closure. The Ansys CFX 19.1 and Ansys Fluent 19.1 software was used to simulate the hydrodynamic analysis and obtain the required results. The hydrodynamic analysis was performed for four opening degrees of gate valve

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