CFD Analysis of Composite Axial Water Turbine

2010 ◽  
Author(s):  
Jifeng Wang ◽  
Norbert Mu¨ller
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Cfd Analysis ◽  
Computational Investigation ◽  
Rotating Speed ◽  
Fundamental Understanding ◽  
Water Turbine ◽  
Water Turbines

This paper presents computational investigation of the flow in composite material axial water turbines using Finite Volume based commercial CFD package namely Fluent. Based on three dimensional numerical flow analysis and fluid-structure interaction, the flow characteristics of water turbines including nozzle, impeller and diffuser are predicted. Two particulare cases are studied and compared. The extract power of water turbine in different rotating speed and water inlet velocity are analyzed. The calculated results will provide a fundamental understanding of the impeller as water turbine, and this design method is used to shorten the design period and improve the water turbine’s performance.

Design of Composite Water Turbine in Free Stream Using CFD

2010 ◽  
Author(s):  
Jifeng Wang ◽  
Marco Vagani ◽  
Norbert Mu¨ller
Keyword(s):  
Free Stream ◽  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Power Coefficient ◽  
Fundamental Understanding ◽  
Water Turbine ◽  
Water Turbines ◽  
Extracted Power

The objective of this paper is to investigate the performance of composite material axial water turbines in a free stream using Fluent, a Finite Volume based commercial CFD package. Based on three dimensional numerical flow analysis and fluid-structure interaction, the flow characteristics of water turbines including a nozzle, impeller and diffuser are predicted. The extracted power coefficient is calculated for water turbines of different tip speed ratios in a free stream of water with inlet velocity of 2.5m/s. The extracted powers of one single turbine unit and an array with ten turbine units are analyzed and compared for different rotating speeds and water inlet velocities. The calculated results will provide a fundamental understanding of the impeller as a water turbine, and this design method is used to shorten the design process and improve the water turbine’s performance.

A Three-Dimensional Viscous Transonic Inverse Design Method

2000 ◽  
Author(s):  
W. T. Tiow ◽  
M. Zangeneh
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Viscous Effects ◽  
Flow Equations ◽  
Flow Solution ◽  
Turbomachinery Blades ◽  
A Cell ◽  
Inverse Design Method ◽  
Euler Solver

The development and application of a three-dimensional inverse methodology is presented for the design of turbomachinery blades. The method is based on the mass-averaged swirl, rV~θ distribution and computes the necessary blade changes directly from the discrepancies between the target and initial distributions. The flow solution and blade modification converge simultaneously giving the final blade geometry and the corresponding steady state flow solution. The flow analysis is performed using a cell-vertex finite volume time-marching algorithm employing the multistage Runge-Kutta integrator in conjunction with accelerating techniques (local time stepping and grid sequencing). To account for viscous effects, dissipative forces are included in the Euler solver using the log-law and mixing length models. The design method can be used with any existing solver solving the same flow equations without any modifications to the blade surface wall boundary condition. Validation of the method has been carried out using a transonic annular turbine nozzle and NASA rotor 67. Finally, the method is demonstrated on the re-design of the blades.

Investigations on the Rotordynamic Characteristics of a Hole-Pattern Seal Using Transient CFD and Periodic Circular Orbit Model

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Xin Yan ◽  
Jun Li ◽  
Zhenping Feng
Keyword(s):  
Circular Orbit ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Numerical Approach ◽  
Deformation Method ◽  
Rotordynamic Coefficients ◽  
Forward Orbit ◽  
Reaction Forces ◽  
Orbit Model

Numerical investigations on the rotordynamic characteristics of a typical hole-pattern seal using transient three-dimensional Reynolds-averaged Navier–Stokes (RANS) solution and the periodic circular orbit model were conducted in this work. The unsteady solutions combined with mesh deformation method were utilized to solve the three-dimensional RANS equations and obtain the transient reaction forces on a typical hole-pattern seal rotor at five different excitation frequencies. The relation between the periodic reaction forces and frequency dependent rotordynamic coefficients of the hole-pattern seal was obtained by considering the rotor with a periodic circular orbit (including forward orbit and backward orbit) of the seal center. The rotordynamic coefficients of the hole-pattern seal were then solved based on the obtained unsteady reaction forces and presented numerical method. Compared with the experimental data, the predicted rotordynamic coefficients of the hole-pattern seal are more agreeable with the experiment than that of the ISO-temperature (ISOT) bulk flow analysis and numerical approach with one-direction-shaking model. Furthermore, the unsteady leakage flow characteristics in the hole-pattern seal were also illustrated and discussed in detail.

CFD Analysis of Batch-Type Reheating Furnace With Regeneratve Burners

2008 ◽  
Author(s):  
Bin Wu ◽  
Tom Roesel ◽  
Andrew M. Arnold ◽  
Zhaojiang Xu ◽  
Eugene Arnold ◽  
...  
Keyword(s):  
Product Quality ◽  
Three Dimensional ◽  
Control Process ◽  
Flow Characteristics ◽  
Steel Production ◽  
Value Added ◽  
Heating Process ◽  
Cfd Analysis ◽  
Reheating Furnace ◽  
Quality Control Process

A reheating furnace is a critical component in value-added steel production. These furnaces can have a significant impact on product quality and total cost. Due to the higher efficiency of regenerative burners, a growing number of reheating furnaces are using this technology. To better understand the regenerative burner operation, a Computational Fluid Dynamics (CFD) analysis has been conducted to examine the transient and three dimensional flow characteristics in the No.3 reheating furnace at ArcelorMittal Steelton. Simulation results with traditional burners and regenerative burners have been analyzed to understand the effect of retrofitting a furnace with these more modern burners. The temperature distribution on the billets has also been monitored throughout the simulated heating process providing insight into the optimization of billet residence time and improvement of the product quality control process.

Experimental Investigation of the Flow Field of a Ceiling Fan

Volume 3 ◽  
2004 ◽  
Author(s):  
Ankur Jain ◽  
Rochan Raj Upadhyay ◽  
Samarth Chandra ◽  
Manish Saini ◽  
Sunil Kale
Keyword(s):  
Experimental Investigation ◽  
Energy Consumption ◽  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Tip Vortex ◽  
Optimal Designs ◽  
Tropical Regions ◽  
Fundamental Understanding ◽  
Blade Tip

A ceiling fan is the predominating comfort provider in tropical regions worldwide. It consists of an assembly of an electric motor with 3–4 blades suspended from the ceiling of a room. Despite its simplicity and widespread use, the flow induced by a ceiling fan in a closed room has not been investigated, and sub-optimal designs are in wide use. There is vast potential for energy conservation and improved comfort by developing optimized fan designs. This work develops a fundamental understanding of the flow characteristics of a ceiling operating inside a closed room. Using smoke from thick incense sticks, the flow field created by the ceiling fan is visualized. In most regions, the flow is periodic and three-dimensional. Vortices are seen to be attached to the blade tip and hub, which reduces downward flow and increases energy consumption. Only the middle 75% of blade actually pushes the air downwards, and the comfort region is limited to a cylinder directly under the blades; velocities in this region were measured with a vane anemometer. Winglets and spikes attached to the blade tip disrupted the tip vortex, and increased downflow by about 13% without any increase in power consumption.

Helium Turboexpander for Cryogenic Refrigeration and Liquefaction Cycles: Transient Analysis of Rotor–Stator Interaction

2016 ◽  
Author(s):  
Ashish Alex Sam ◽  
Parthasarathi Ghosh
Keyword(s):  
Turbulent Flows ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Space Length ◽  
Turbine Wheel ◽  
Mechanical Constraints ◽  
Computational Fluid Dynamics Analysis ◽  
Flow Mechanisms ◽  
Rotor Stator Interaction

Computational fluid dynamics analysis of the complex flows in a cryogenic turboexpander is essential for any improvement in its performance. This includes a detailed analysis of the unsteady turbulent flows imparted mainly by the rotor stator interactions. The flow unsteadiness due to rotor stator interaction is caused by the relative motion between the stationary and rotating component, interaction of the turbine wheel blades with the wakes and vortices generated by the upstream blades and at trailing edges. In order to minimize the loss generation due to this unsteadiness, the vaneless space length at the nozzle-turbine wheel interface and the length of the straightening portion at the turbine wheel-diffuser interface should be optimised considering the mechanical constraints. In this paper three dimensional unsteady viscous flow analysis of a helium cryogenic turboexpander was carried out using Ansys CFX to investigate the origin and flow mechanisms that cause these unsteady phenomena. The analysis has been done for three different lengths of straightening duct at the turbine wheel diffuser interface. The performance parameters from the computational results were compared and analysed to understand the flow characteristics in each case.

A High-Order LES Turbulent Model to Study Unsteady Flow Characteristics in a High Pressure Turbine Cascade

2008 ◽  
Author(s):  
Tomohiko Jimbo ◽  
Debasish Biswas ◽  
Yasuyuki Yokono ◽  
Yoshiki Niizeki
Keyword(s):  
Physical Process ◽  
Pressure Loss ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Measured Data ◽  
High Order ◽  
Turbulent Model ◽  
Loss Mechanism

In this work, unsteady viscous flow analysis around turbine blade cascade using a High-Order LES turbulent model is carried out to investigate basic physical process involved in the pressure loss mechanism. This numerical analysis is assessed to the wind tunnel cascade test. Basically, all the physical phenomena occurring in nature are the effect of some cause, and the effect can somehow be measured. However, to understand the cause, detail information regarding the visualization of the phenomena, which are difficult to measure, are necessary. Therefore, in our work, firstly the computed results are compared with the measured data, which are the final outcome of the cause (of the phenomena under investigation), to verify whether our physics-based model could qualitatively predict the measured facts or not. It was found that the present model could well predict measured data. Therefore, the rest of the computed information, which were difficult to measure, were used to visualize the overall flow behavior for acquiring some knowledge of the physical process associated with the pressure loss mechanism. Our study led to an understanding that the interaction of the vortex generated on the suction and pressure surface of the blade and the secondary vortex generated on the end-wall, downstream the trailing edge resulted in the formation of a large vortex structure in this region. This unsteady three-dimensional flow characteristic is expected to play an important role in the pressure loss mechanism.

Design of a Modern Test-Facility for LPT/OGV Flows

2003 ◽  
Author(s):  
Johan Hja¨rne ◽  
Jonas Larsson ◽  
Lennart Lo¨fdahl
Keyword(s):  
Test Section ◽  
Design Method ◽  
Guide Vane ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Design Procedure ◽  
Test Facility ◽  
Settling Chamber ◽  
Inlet Section ◽  
Analytical Approaches

This paper presents a complete design process of a modern test-facility for the investigation of low pressure turbine/outlet guide vane (LPT/OGV) flows. The design is based on modern CFD techniques combined with classical analytical approaches and experimental expertise. The paper describes the design procedure of the diffuser, the settling chamber, the contraction, the inlet section with boundary layer bleeds and the test-section. In the contraction part of the paper a new design method is developed using both separation and relaminarization theory. Finally, full viscous three-dimensional CFD calculations are performed of the test-facility, from the contraction to the test-section, making it possible to assess the flow characteristics of the test-facility before it is even constructed.

Three-dimensional simulation and experimental investigation of three-dimensional printed guiding devices on lattice-apron compact spinning

2020 ◽  
pp. 004051752098258
Author(s):  
Malik YH Saty ◽  
Nicholus Tayari Akankwasa ◽  
Jun Wang
Keyword(s):  
Experimental Investigation ◽  
Air Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Yarn Properties ◽  
3D Printed ◽  
Dimensional Simulation ◽  
Compact Spinning ◽  
Set Up

The compact spinning system with a lattice apron utilizes air-flow dynamics to condense fibers in a bunch and enhance the yarn properties. One of the main challenges with this method is the lack of a comprehensive understanding of the air-flow field's effect in the condensing zone. This work presents a numerical and experimental investigation of the effects of three-dimensional (3D) printed guiding devices on the air-flow characteristics and yarn properties. Firstly, the 3D numerical model of the compact spinning system was set up based on the compact spinning machine geometrical dimensions. Secondly, different 3D prototypes were developed, simulated, and analyzed using computational fluid dynamics based on ANSYS software. The prototypes (A-type, B-type, and C-type), selected according to the simulation results, were then 3D printed to enable further experimental investigation. Air-flow analysis results in the air-suction flume area exhibiting a very high negative pressure, and the centerline zone was characterized by high velocity. Experimental results revealed that the three yarns spun with guiding devices had better strength, hairiness, and evenness than those spun without a guiding device. The model developed can be further improved and utilized for commercial purposes and is anticipated to improve compact spun yarn properties significantly.

Performance Prediction and Design Method for Centrifugal Pump Based on Computational Fluid Dynamics

2010 ◽  
Vol 97-101 ◽  
pp. 3463-3466
Author(s):  
Chun Lei Shao ◽  
Bo Qin Gu ◽  
X.L. Huang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Pump ◽  
Performance Prediction ◽  
Design Method ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Prediction Method ◽  
Design Quality ◽  
Advantages And Disadvantages

Using Reynolds average N-S equations closed by standard k- turbulence model, the steady and unsteady turbulent flow in centrifugal pump was simulated by using MRF model and SM model respectively. A method for predicting the performances of centrifugal pump was built on the basis of computational fluid dynamics. By the presented performance prediction method, not only the flow characteristics of centrifugal pump can be obtained, but also can its performances be evaluated quantitatively and qualitatively. The advantages and disadvantages of some traditional design methods for centrifugal pump were analyzed. On the basis of performance prediction and flow analysis, a new design method was put forward in consideration of the steady and unsteady performances of centrifugal pump. The proposed method can be used to design the centrifugal pump with high running stability, efficiency and cavitation resistance, and it is available for shortening development period and improving design quality of pump.

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