HYDRAULIC DESIGN AND ANALYSIS OF THE SAXO-TYPE VERTICAL AXIAL TURBINE

2011 ◽  
Vol 35 (1) ◽  
pp. 119-143 ◽  
Author(s):  
Edvard Höfler ◽  
Janez Gale ◽  
Anton Bergant
Keyword(s):  
Cfd Simulation ◽  
Design Method ◽  
Guide Vane ◽  
Design Procedure ◽  
Axial Turbine ◽  
Streamline Curvature ◽  
Runner Blade ◽  
Hydraulic Design ◽  
Through Flow ◽  
Blade Row

The paper presents a procedure for hydraulic design and analysis of the blade geometry of a high specific speed runner of the Saxo-type double-regulated vertical axial turbine. The meridional through-flow in the passage from the conical guide vane apparatus to the draft-tube elbow is designed by a streamline curvature method (SCM). To validate the design method and predictions and to investigate the design duty point and a number of off-design operating regimes, an extensive CFD simulation inside the entire turbine water-passage is performed. The flow patterns downstream the guide vane apparatus and the runner exit flow are analyzed. The focus of the analysis is on distribution of the angular momentum alongside the turbine, as well as on its impact on the flow around the runner blades. The SCM design procedure presented in the paper proves to be a robust and accurate tool for the runner blade row design.

scholarly journals Through-Flow Analysis for Axial-Stage Design Including Streamline-Slope Effects

1993 ◽  
Author(s):  
Theodosios Korakianitis ◽  
Dequan Zou
Keyword(s):  
Mass Flow ◽  
Three Dimensional ◽  
Momentum Equation ◽  
Total Enthalpy ◽  
Streamline Curvature ◽  
Flow Balance ◽  
Through Flow ◽  
Blade Row ◽  
Iteration Loop ◽  
Predictor Corrector

This paper presents a new method to design (or analyze) subsonic or supersonic axial compressor and turbine stages and their three-dimensional velocity diagrams from hub to tip by solving the three-dimensional radial-momentum equation. Some previous methods (matrix through-flow based on the streamfunction approach) can not handle locally supersonic flows, and they are computationally intensive when they require the inversion of large matrices. Other previous methods (streamline curvature) require two nested iteration loops to provide a converged solution: an outside iteration loop for the mass-flow balance; and an inside iteration loop to solve the radial momentum equation at each flow station. The present method is of the streamline-curvature category. It still requires the iteration loop for the mass-flow balance, but the radial momentum equation at each flow station is solved using a one-pass numerical predictor-corrector technique, thus reducing the computational effort substantially. The method takes into account the axial slope of the streamlines. Main design characteristics such as the mass-flow rate, total properties at component inlet, hub-to-tip ratio at component inlet, total enthalpy change for each stage, and the expected efficiency of each streamline at each stage are inputs to the method. Other inputs are the radial position and axial velocity component at one surface of revolution through the axial stages. These can be provided for either the hub, or the mean, or the tip location of the blading. In addition the user specifies the azimuthal deflection of the flow from the axial direction at each radius (or as a function of radius) at each blade row inlet and outlet. By construction the method eliminates radial variations of total enthalpy (work) and entropy at each blade row inlet and outlet. In an alternative formulation enthalpy variations across radial positions at each axial station are included in the analysis. The remaining three-dimensional velocity diagrams from hub to tip, and the radial location of the remaining streamlines, are obtained by solving the momentum equation using a predictor-corrector method. Examples for one turbine and one compressor design are included.

scholarly journals Semi-Inverse Design of Compressor Cascades, Including Supersonic Inflow

1990 ◽  
Author(s):  
A. Kirschner ◽  
H. Stoff
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Design Procedure ◽  
Meridional Plane ◽  
Simple Method ◽  
Blade Loading ◽  
Through Flow ◽  
Blade Element

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.

Hydraulic Characteristics of the New Type Bulb Turbine With Micro-Head

2013 ◽  
Author(s):  
Lingyu Li ◽  
Yuan Zheng ◽  
Daqing Zhou ◽  
Zihao Mi
Keyword(s):  
Numerical Simulation ◽  
Cfd Simulation ◽  
Guide Vane ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Three Dimensions ◽  
Guide Vanes ◽  
Runner Blade ◽  
Cfd Method ◽  
Bulb Turbine

The head of low-head hydropower stations is generally higher than 2.5m in the world, while micro-head hydropower resources which head is less than 2.5m are also very rich. In the paper, three-dimensional CFD method has been used to simulate flow passage of the micro-head bulb turbine. The design head and unit flow of the turbine was 1m and 3m3/s respectively. With the numerical simulation, the bulb turbine is researched by analyzing external characteristics of the bulb turbine, flow distribution before the runner, pressure distribution of the runner blade surface, and flow distribution of the outlet conduit under three different schemes. The turbine in second scheme was test by manufactured into a physical model. According to the results of numerical simulation and model test, bulb turbine with no guide vane in second scheme has simpler structure, lower cost, and better flow capacity than first scheme, which has traditional multi-guide vanes. Meanwhile, efficiency of second scheme has just little decrease. The results of three dimensions CFD simulation and test results agree well in second scheme, and higher efficiency is up to 77% which has a wider area with the head of 1m. The curved supports in third scheme are combined guide vanes to the fixed supports based on 2nd scheme. By the water circulations flowing along the curved supports which improve energy transformation ability of the runner, the efficiency of the turbine in third scheme is up to 82.6%. Third scheme, which has simpler structure and best performance, is appropriate for the development and utilization of micro-head hydropower resources in plains and oceans.

Wave Rotor Design Method With Three Steps Including Experimental Validation

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Shining Chan ◽  
Huoxing Liu ◽  
Fei Xing ◽  
Hang Song
Keyword(s):  
Experimental Method ◽  
Experimental Validation ◽  
Cfd Simulation ◽  
Design Method ◽  
Flow Characteristics ◽  
Design Procedure ◽  
Wave Rotor ◽  
Rotor Design ◽  
Design Function ◽  
Analytic Design

This paper adapted and extended the preliminary two-step wave rotor design method with another step of experimental validation so that it became a self-validating wave rotor design method with three steps. First, the analytic design based on unsteady pressure wave models was elucidated and adapted to a design function. It was quick and convenient for a first prediction of the wave rotor. Second, the computational fluid dynamics (CFD) simulation was adapted so that it helped to adjust the first prediction. It provided detailed information of the wave rotor inner flow. Thirdly, an experimental method was proposed to complement the validation of the wave rotor design. This experimental method realized tracing the pressure waves and the flows in the wave rotor with measurement on pressure and temperature distributions. The critical point of the experiment is that the essential flow characteristics in the rotor were reflected by the measurements in the static ports. In all, the three steps compensated for each other in a global design procedure, and formed an applicable design method for generic cases.

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.

A Compressible Three-Dimensional Inverse Design Method Based on the Streamline Curvature Approach and Clebsch Formulation for Radial and Mixed Flow Turbomachines

2012 ◽  
Author(s):  
Xiao Pei Tian ◽  
Peng Shan
Keyword(s):  
Flow Field ◽  
Inverse Method ◽  
Design Method ◽  
Inverse Design ◽  
Periodic Flow ◽  
Mixed Flow ◽  
3 Dimensional ◽  
Streamline Curvature ◽  
Through Flow ◽  
Inverse Design Method

The through-flow inverse design method based on the streamline curvature approach is nowadays a widely used quasi-3-dimensional blades design method for radial and mixed flow turbomachines. The main limitation of this method is using the flow field on the mean stream surface S2,m to approximate the actual 3-dimensional flow field. Without an effective description of the periodic flow, it is impossible for this method to realize exactly the prescribed circumferentially averaged swirl rVθ. Is there any way to develop this classical through-flow inverse method to a 3-dimensional one conveniently? The answer is yes. A new compressible 3-dimensional inverse design method for radial and mixed flow turbomachines is presented in this paper. This new 3-dimensional inverse method provides a convenient and effective way to obtain the periodic flow field for the streamline curvature through-flow inverse method. Meanwhile, compared with another type of similar 3-dimensional inverse method firstly described by Tan etc. based on Stokes stream functions and Monge potential functions from the Clebsch formulation to calculate the circumferentially averaged flow and the periodic flow respectively, this new method has its own advantages. In order to assess the usefulness of the new method, four centrifugal impellers are designed under the same design specifications by four different inverse methods respectively. They are two quasi-3-dimensional streamline curvature through-flow inverse methods without and with a slip factor model, a 3-dimensional approximated inverse approach based on stream functions and Monge potential functions and the 3-dimensional inverse method presented here. The performances of the four impellers yielding from a RANS commercial solver are compared. The capabilities of the four methods to realize the target circumferentially averaged swirl are also studied.

Study on Overall Design of a Vertical Take-Off and Landing Unmanned Aerial Vehicle Powered by Electric Ducted Fans

2021 ◽  
Author(s):  
Tawei Chou ◽  
Qiyu Ying ◽  
Yuping Qian ◽  
Weilin Zhuge ◽  
Yangjun Zhang
Keyword(s):  
Power Unit ◽  
Unmanned Aerial Vehicle ◽  
Cfd Simulation ◽  
Design Method ◽  
Load Capacity ◽  
Design Procedure ◽  
Low Noise ◽  
Overall Design ◽  
Ducted Fan ◽  
Aerial Vehicle

Abstract Facing the growing traffic fleet in the cities nowadays, it is believed that three-dimensional urban transportation could be a solution and will be introduced in the near future. Vertical take-off and landing flying platforms powered by ducted fans will attract increasingly attention because it has advantages on high propulsion efficiency, low noise, and better safety. However, unlike traditional open-blade multi-rotor drones, ducted fan drones lack a systematic design approach that comprehensively considers the overall system performance and the power unit efficiency. Current design procedure leads to insufficient load capacity and low efficiency systems. This paper proposes an overall design method for a ducted fan-type vertical take-off and landing flight platform. The ducted fan and motor of the core power unit are designed and selected aiming at improving aerodynamic efficiency and structural utilization of the system. A heavy-load vertical take-off and landing Unmanned Aerial Vehicle (UAV) powered by ducted fans with a take-off weight of 450kg is designed based on this method. CFD simulation is utilized to calculate the performance of the designed Unmanned Aerial Vehicle, and finite element analysis is carried out to examine the overall strength safety. The final design results show that the overall design method plays a great role in the development of ducted fan UAV.

A Hydraulic Design Procedure of Axial-Flow Pump

2015 ◽  
Author(s):  
Zhenhua Shen ◽  
Svend Rasmussen ◽  
Xiaofen Ma ◽  
Christian Brix Jacobsen
Keyword(s):  
High Efficiency ◽  
Guide Vane ◽  
Axial Flow ◽  
Design Procedure ◽  
Visual Basic ◽  
Cnc Machining ◽  
Pump Design ◽  
Hydraulic Design ◽  
Axial Flow Pump ◽  
Flow Pump

A radical decrease of the product development time has been achieved by implementation of simulation driven development on axial-flow pump design. A new automatic hydraulic design procedure of axial-flow pumps was developed. It consists of in-house developed parametric design template, Visual Basic macro, OpenFOAM and an in-house developed pump performance plot tool. In this procedure the parametric template includes propeller design and guide vane design. A mesh is generated by using OpenFOAM snappyHexMesh utility. Visual Basic macro is used to link the parametric template and OpenFOAM. In order to validate the accuracy of predicting the hydraulic performance from this procedure, a high specific speed axial-flow pump was designed by using this procedure and an in-house optimization tool. Finally an aluminum scaled prototype was made by CNC machining. The CFD results show that BEP efficiency is equal to 83.5%, and testing shown BEP efficiency of 85%. It indicates that the hydraulic design from this procedure is both reliable and able to produce high efficiency designs.

scholarly journals An extension of the streamline curvature through-flow design method for bypass fans of turbofan engines

2016 ◽  
Vol 231 (2) ◽  
pp. 240-253 ◽  
Author(s):  
Sercan Acarer ◽  
Ünver Özkol
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Design Method ◽  
Three Dimensional ◽  
Simple Extension ◽  
Two Dimensional ◽  
Turbofan Engines ◽  
Streamline Curvature ◽  
Through Flow ◽  
Numerical Effort

The two-dimensional through-flow modeling of turbomachinery is still one of the most powerful tools available to the turbomachinery industry for aerodynamic design, analysis, and post-processing of test data due to its robustness and speed. Although variety of aspects of such a modeling approach are discussed in the publicly available literature for compressors and turbines, not much emphasis is placed on combined modeling of the fan and the downstream splitter of turbofan engines. The current article addresses this void by presenting a streamline curvature through-flow methodology that is suitable for inverse design for such a problem. A new split-flow method for the streamline solver, alternative to the publicly available analysis-oriented method, is implemented and initially compared with two-dimensional axisymmetric computational fluid dynamics on two representative geometries for high and low bypass ratios. The empirical models for incidence, deviation, loss, and end-wall blockage are compiled from the literature and calibrated against two test cases: experimental data of NASA two-stage fan and three-dimensional computational fluid dynamics of a custom-designed transonic fan stage. Finally, experimental validation against GE-NASA bypass fan case is accomplished to validate the complete methodology. The proposed method is a simple extension of streamline curvature method and can be applied to existing compressor methodologies with minimum numerical effort.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

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