scholarly journals FIELD OBSERVATION AND NUMERICAL SIMULATION OF BARRIER ISLAND FORMATION AS RESULT OF ELONGATION OF SAND SPIT AND ITS ATTACHMENT TO OPPOSITE SHORE

2017 ◽  
pp. 5 ◽  
Author(s):  
Shiho Miyahara ◽  
Takaaki Uda ◽  
Masumi Serizawa
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Barrier Island ◽  
Aerial Photographs ◽  
Supply Source ◽  
Dredged Materials ◽  
Sand Spit ◽  
Sand And Gravel ◽  
Suo Nada ◽  
Good Agreement

An artificial mound was produced from dredged materials containing sand and gravel in the Nakatsu tidal flat facing the Suo-nada Sea, and this artificial mound served as a supply source of sediment for the development of a barrier island. A sand spit extended from this mound in an extremely shallow sea and attached to the opposite shore, resulting in the formation of a barrier island. The planar changes in the sand spit were investigated using aerial photographs. Observations were compared with the results of a numerical simulation regarding the formation of a barrier island on a sloping bed with a 1/40 slope using the BG model (a model for predicting three-dimensional beach changes based on Bagnold’s concept). The observed change in the barrier island and the calculated results were in good agreement.

Numerical and Experimental Evaluation of Turbulent Flow in Volute

2003 ◽  
Author(s):  
Akitomo Igarashi ◽  
Kazuyuki Toda ◽  
Makoto Yamamoto ◽  
Toshimichi Sakai
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Three Dimensional ◽  
Experimental Result ◽  
Centrifugal Fan ◽  
Flow Conditions ◽  
Flow Angle ◽  
Fan Performance ◽  
Centrifugal Fans ◽  
Good Agreement

The performance of centrifugal fans is considerably influenced by the design of tongue at the re-circulation port. The flow in the volute of a centrifugal fan was studied both experimentally and numerically. In this experiment, flow angle, pressure and velocity profiles were measured at a large number of locations in the volute. The flow field in the volute passage was analyzed using Computational Fluid Dynamics. The flow was assumed to be three dimensional, turbulent and steady. The numerical simulation produced qualitatively good agreement with the experimental result. The results from experiment and numerical simulation indicated that the adoption of a re-circulating flow port improved fan performance for all flow conditions. In addition, the existence of strong secondary flow was apparent at the cross-section of the volute passage.

Numerical Simulation of Synthetic Heat Transfer in Laminar Nanofluid in a Horizontal Pipe

2014 ◽  
Vol 936 ◽  
pp. 409-414
Author(s):  
Mohsen Mirzaei ◽  
Mostafa Jafari Gishin ◽  
Mohammad Abbaspour
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Convective Heat Transfer Coefficient ◽  
Three Dimensional ◽  
Oxide Nanoparticles ◽  
Aluminum Oxide Nanoparticles ◽  
Horizontal Pipe ◽  
Water Based ◽  
Solid Liquid ◽  
Good Agreement

In this study, the effect of solid-liquid volumetric ratio in laminar flow of nanofluid has been investigated numerically. The conservation equations are utilized in three dimensional elliptical forms for laminar and steady flow, and the effects of adding aluminum oxide nanoparticles to water based-fluid are studied. First, the influence of solid-liquid volumetric ratio on the secondary flow vortices, non-dimensional temperature is investigated for a flow with a fixed low Reynolds number and different Grashof numbers in a horizontal pipe. Then, the effect of variation in solid-liquid volumetric ratio on Nusselt number and convective heat transfer coefficient along the pipe is studied. The results of this study are in good agreement with the current literatures.

PARALLEL SIMULATION OF EXPLOSION IN AN UNLIMITED ATMOSPHERE

2010 ◽  
Vol 24 (13) ◽  
pp. 1349-1352 ◽  
Author(s):  
TIANBAO MA ◽  
CHENG WANG ◽  
GUANGLEI FEI ◽  
JIANGUO NING
Keyword(s):  
Numerical Simulation ◽  
Parallel Algorithm ◽  
Large Scale ◽  
Three Dimensional ◽  
Parallel Simulation ◽  
Data Dependency ◽  
Empirical Results ◽  
Parallel Speedup ◽  
Good Agreement ◽  
Impact Problem

In this paper, a parallel Eulerian hydrocode for the simulation of large scale complicated explosion and impact problem is developed. The data dependency in the parallel algorithm is studied in particular. As a test, the three dimensional numerical simulation of the explosion field in an unlimited atmosphere is performed. The numerical results are in good agreement with the empirical results, indicating that the proposed parallel algorithm in this paper is valid. Finally, the parallel speedup and parallel efficiency under different dividing domain areas are analyzed.

Numerical Simulation of a Pouring Flow From a Beverage Can

2019 ◽  
Author(s):  
Yu Nishio ◽  
Keiji Niwa ◽  
Takanobu Ogawa
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Angular Speed ◽  
Experimental Result ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Numerical Result ◽  
Liquid Flows ◽  
Good Agreement

Abstract Motion of liquid pouring from a beverage can is numerically studied. A liquid is poured from a can which is rotated at a prescribed angular speed. The flow is simulated by solving the unsteady three-dimensional Navier-Stokes equations. An experiment under the same condition is also carried out to validate the computational result. The result shows that, when the can is tipped, the liquid flows over the lid of the can and is once obstructed by the rim of the lid. The numerical result is in good agreement with the experimental result. The effect of condensation formed on a can surface is also considered. The effect of condensation is taken into account by adjusting a contact angle. The liquid pouring from a can trickles down along the can body. The computation reproduces these experimental observations.

Numerical Simulation of Impeller–Volute Interaction in Centrifugal Compressors

1999 ◽  
Vol 121 (3) ◽  
pp. 603-608 ◽  
Author(s):  
K. Hillewaert ◽  
R. A. Van den Braembussche
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Flow Calculation ◽  
Total Temperature ◽  
Temperature And Pressure ◽  
Good Agreement

A numerical procedure to predict the impeller–volute interaction in a single-stage centrifugal compressor is presented. The method couples a three-dimensional unsteady flow calculation in the impeller with a three-dimensional time-averaged flow calculation in the volute through an iterative updating of the boundary conditions on the interface of both calculation domains. The method has been used to calculate the flow in a compressor with an external volute at off-design operation. Computed circumferential variations of flow angles, total temperature, and pressure are shown and compared with measurements. The good agreement between the predictions and measurements confirms the validity of the approach.

The Experimental Study and Numerical Simulation of Turbulent Flow in Pumping Forebay

2009 ◽  
Author(s):  
Chao Liu ◽  
Jiren Zhou ◽  
Li Cheng
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Turbulent Flow ◽  
Three Dimensional ◽  
Computational Results ◽  
Experiment Study ◽  
Study Results ◽  
Measurement Results ◽  
Good Agreement ◽  
Made In

The experiment study was made to optimize the design of a pumping forebay. The Combined-sills were made in the forebay to eliminate the circulation and vortices of the diffusing flow successfully. The Numerical simulation of three-dimensional turbulent flow is applied on the complicate fore-and-aft flow of sills. The computational results are compared with the measurement results of physical model. The calculated results are in good agreement with the experimental data. The flow pattern is obviously improved. The study results have been applied in the project which gives a uniform approach flow to the pumping sump.

Three-Dimensional Numerical Simulation of the Hydraulic Characteristics of Spillway in Gushitan Reservoir

2012 ◽  
Vol 256-259 ◽  
pp. 2403-2406
Author(s):  
Shu Guang Jing ◽  
Xue Ping Gao ◽  
Lai Fei Jia ◽  
Li Ping Xu
Keyword(s):  
Numerical Simulation ◽  
Water Surface ◽  
Three Dimensional ◽  
Simulation Method ◽  
Vof Method ◽  
Hydraulic Characteristics ◽  
Bottom Pressure ◽  
Surface Profiles ◽  
Simulation Results ◽  
Good Agreement

Based on standard k-ε turbulence model and the VOF method for tracking free surface, hydraulic characteristics of the spillway in Gushitan Reservoir are simulated with a 3-D numerical model. The discharge capacity, water surface profiles, bottom pressure distribution and flow pattern are studied. Numerical simulation results have been in good agreement with experimental results, showing fine feasibility to study hydraulic characteristics of the spillway with the VOF method. The hydraulic characteristics acquired by the numerical simulation method can be used for spillway design.

Nuclide u Transport in Radioactive Waste Disposal Field with Weak Permeable Media

2013 ◽  
Vol 353-356 ◽  
pp. 1175-1178
Author(s):  
Ying Er Deng ◽  
Wei Zhang ◽  
Ying Zi Chen
Keyword(s):  
Numerical Simulation ◽  
Radioactive Waste ◽  
Conceptual Model ◽  
Waste Disposal ◽  
Three Dimensional ◽  
Scientific Basis ◽  
Radioactive Waste Disposal ◽  
Prevention Measures ◽  
Permeable Media ◽  
Good Agreement

This paper took nuclide U as a research object and focused on nuclide U transport. Three-dimensional conceptual model was established for nuclide U transport in certain a radioactive waste disposal field with weak permeable media. Nuclide U transport in the field was studied by means of three-dimensional numerical simulation. Results show that there is good agreement between numerical simulated and observed groundwater level and that the conceptual model and the numerical simulation are reasonable. Nuclide U transport in the field will form a pollution zone after about 10 years in the mainstream direction and pollute groundwater of the southern area. Prevention measures should be adopted for nuclide U transport in the field. The results can provide evaluation of engineering safety of nuclide U transport in the field with scientific basis.

scholarly journals Three-Dimensional Numerical Simulations of Buoyant Jets Discharged from a Rosette-Type Multiport Diffuser

2019 ◽  
Vol 7 (11) ◽  
pp. 409 ◽  
Author(s):  
Xiaohui Yan ◽  
Abdolmajid Mohammadian ◽  
Xin Chen
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Computational Cost ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Ambient Water ◽  
Mixing Processes ◽  
Buoyant Jets ◽  
Practical Applications ◽  
Good Agreement

In some outfall systems, wastewaters are discharged into ambient water bodies using rosette-type diffusers in the form of multiple buoyant jets, and it is essential to simulate their mixing characteristics for practical applications and optimal design purposes. The mixing processes of a rosette jet group are more complicated than single jets and multiple horizontal or vertical jets, and thus the existing methods cannot be effectively used to simulate their mixing and dilution properties. With the recent advancements in numerical modeling approaches, numerical simulation of wastewater jets as three-dimensional phenomena can be feasible. The present study deals with a fully three-dimensional numerical simulation for buoyant jets discharged from a rosette-type multiport diffuser, with the standard and re-normalization group (RNG) k-ε turbulence models. The simulated results are compared with experimental data, and the results show a good agreement with the experimental data, demonstrating that the numerical model is an efficient and effective tool for simulating rosette jet groups. It was also concluded that the RNG k-ε model leads to better results than the standard k-ε model with a comparable computational cost. The validated model was further utilized to investigate the influences of port inclinations on the mixing behaviors.

Calculation and Analysis of Submersible Well Pump Clearance Leakage Loss

2013 ◽  
Vol 456 ◽  
pp. 225-229
Author(s):  
Xiong Fa Gao ◽  
Wei Dong Shi ◽  
Qi Hua Zhang ◽  
De Sheng Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Empirical Formula ◽  
Guide Vane ◽  
Three Dimensional ◽  
Integral Model ◽  
Leakage Loss ◽  
Second Stage ◽  
External Characteristics ◽  
Good Agreement

The 200QJ80-22 submersible well pump was investigated to predict the effects of leakage change of the submersible well pump on external characteristics. The integral model of impeller, guide vane and wear-ring was established and the numerical simulation for three-dimensional whole flow field was carried out. The results show that the predicted results have a good agreement with the experimental data. The result of the numerical simulation shows that the head and efficiency of pump decrease with the size of clearance increasing. Especially when the size of clearance is larger than 0.7 mm, the decreasing becomes more obvious. The leakage calculated through numerical simulation were compared with the values obtained according to empirical formula and the results indicates internal clearance leakage at design point is close to the value calculated through empirical formula in smaller wear-ring clearance, but the simulated values of leakage have a small gap with calculated value obtained from empirical formula. Simultaneously, the Second stage leakage decrease significantly compared to the first stage leakage with the flow rate increasing, while the values got by the empirical formula have a small gap with simulated values obtained.

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