scholarly journals A Study on the Through-Flow Analysis for a Multi-Stage Axial Turbine Considering Leakage Flows

2018 ◽  
Vol 22 (5) ◽  
pp. 1-12
Author(s):  
Sangjo Kim ◽  
Kuisoon Kim ◽  
Changmin Son
Keyword(s):  
Flow Analysis ◽  
Axial Turbine ◽  
Leakage Flows ◽  
Multi Stage ◽  
Through Flow

Flow Passage Modification and Experimental Verification of a Multi-Stage Centrifugal Pump

2013 ◽  
Vol 753-755 ◽  
pp. 2766-2769
Author(s):  
Quan Zhang ◽  
Zhi Jun Shuai ◽  
Pan Zhou ◽  
Wan You Li
Keyword(s):  
Centrifugal Pump ◽  
Cfd Simulation ◽  
Acceleration Response ◽  
Vibration Acceleration ◽  
Flow Passage ◽  
Fluid Field ◽  
Multi Stage ◽  
Through Flow ◽  
Seat Vibration ◽  
Velocity Pressure

In this paper the seat vibration acceleration response was reduced through flow passage modification of the centrifugal pump which could decrease the fluid excitation of the pump. CFD simulation technology was applied to optimize the fluid field of the multi-stage centrifugal pump, and then the velocity, pressure fluctuation and fluid excitation were concerned to investigate the effect of optimization. Finally, the influence of fluid field modification on the seat vibration response was verified experimentally.

Automated Blade Optimization and 3D CFD Analysis for an Axial Multistage GT Compressor Redesign

2006 ◽  
Author(s):  
Lars Moberg ◽  
Gianfranco Guidati ◽  
Sasha Savic
Keyword(s):  
Flow Analysis ◽  
Optimization Methods ◽  
Design System ◽  
Cfd Analysis ◽  
Controlled Diffusion ◽  
Repetitive Tasks ◽  
Blade Optimization ◽  
Through Flow ◽  
Compressor Design ◽  
Linux Cluster

This paper focuses on (1) the basic compressor layout based on meridional through flow analysis and (2) the re-design of blades and vanes using sophisticated automated design optimization methods. All tools and processes are integrated into a consistent Compressor Design System, which runs on a powerful Linux cluster. This design system allows designing, analyzing and documenting blade design in mostly automated way. This frees the engineer from repetitive tasks and allows him to concentrate on a physical understanding and improvement of the compressor. The tools and methods are illustrated on the basis of an actual ALSTOM compressor. The main objectives of this upgrade are a modest increase in mass flow and an efficiency improvement. The latter is to be achieved through the replacement of NACA blades by modern Controlled Diffusion Airfoils (CDA). Results are presented including a CFD analysis of the front stages of the baseline and upgrade compressor.

scholarly journals Numerical Simulation of Cascade Flow: Vortex Element Method for Inviscid Flow Analysis and Axial Turbine Blade Design

2021 ◽  
Vol 85 (2) ◽  
pp. 14-23
Author(s):  
Nono Suprayetno ◽  
Priyono Sutikno ◽  
Nathanael P. Tandian ◽  
Firman Hartono
Keyword(s):  
Best Practice ◽  
Lift Coefficient ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Turbine Rotor ◽  
Design Stage ◽  
Outer Diameter ◽  
Axial Turbine ◽  
Cascade Flow

This study aims to design an axial turbine rotor blade and predict the turbine performance at preliminary design stage. Quasi three dimensional method was applied to design including blade to blade flow analysis. The blade profile uses a NACA 0015 airfoil by varying the profile thickness from hub to tip. The profile is divided into eleven segments which has different parameters. The profile was analysed using blade to blade flow/cascade flow analysis called vortex panel method to obtain lift coefficient. The analysis of cascade flow was performed in potential flow and prediction of turbine perfomance is carried out involving common best practice to give drag effect on the blade. The design of the turbine was applied on three different rotors, which also have a different discharge, head, and design rotation. The outer diameter of turbine 1 is 0.65 m, while turbine 2 and turbine 3 have an outer diameter of 0,60 m. The calculation result show that the efficiency of turbines 1, 2, and 3 were 88,32%, 89,67%, and 89,04%, respectively.

scholarly journals Design of Compressor Endwall Velocity Triangles

2016 ◽  
Author(s):  
Kiran Auchoybur ◽  
Robert J. Miller
Keyword(s):  
Flow Region ◽  
Degree Of Freedom ◽  
Diffusion Limit ◽  
Local Geometry ◽  
High Entropy ◽  
Operating Range ◽  
Leakage Flows ◽  
Multi Stage ◽  
Blade Row ◽  
Inlet Conditions

Near the endwalls of multi-stage compressor blade rows, there is a spanwise region of low momentum, high entropy fluid which develops due to the presence of annulus walls, leakage flows and corner separations. Off-design this region, known as the endwall flow region, often grows rapidly and in practice sets the compressor’s operating range. By contrast, over the operating range of the compressor, the freestream region of the flow is not usually close to its diffusion limit and has little effect on overall range. In light of these two distinct flow regions within a bladerow, this paper considers how velocity triangles in the endwall region should be designed to give a more balanced spanwise failure across the blade span. In the first part of the paper, the sensitivity of the operating flow range of a single blade row to variations in realistic multistage inlet conditions and endwall geometry is investigated. It is shown that the operating range of the blade row is largely controlled by the size and structure of the endwall ‘repeating stage’ inlet boundary layer and not the detailed local geometry within the blade row. In the second part of the paper the traditional design process is ‘flipped’. Instead of redesigning a blade’s endwall geometry to cope with a particular inlet profile into the blade row, the endwall region is redesigned in the multi-stage environment to ‘tailor’ the inlet profile into downstream blade rows. This is shown to allow an extra degree of freedom not usually open to the designer. This extra degree of freedom is exploited to balance freestream and endwall operating range, resulting in a compressor having an increased operating range of ∼20%. If this increased operating range is traded with reduced blade count, it is shown that a design efficiency improvement of Δη∼0.5% can be unlocked.

Design-Optimization Approach to Multistage Axial Contra-Rotating Turbines

2013 ◽  
Author(s):  
Ernesto Sozio ◽  
Tom Verstraete ◽  
Guillermo Paniagua
Keyword(s):  
High Speed ◽  
Differential Evolution Algorithm ◽  
Design Procedure ◽  
Second Step ◽  
Optimization Approach ◽  
Rocket Engines ◽  
Multi Stage ◽  
Through Flow ◽  
Evolution Algorithm ◽  
Turbine Airfoils

Air Turbo Rocket engines, suitable for high-speed propulsion, require compact turbomachinery. This paper presents the design of an innovative multi-stage turbine mounted at the hub of a counter-rotating fan. Hence, the turbine airfoils are required to deliver high torque at low peripheral speeds. The design methodology specifically developed for this fourteen-stage turbine relies on two successive optimization cycles. The first one is based on a through-flow 1D code. This optimization cycle explores a vast set of possible design solutions. In a second step, an optimization using a 3D high fidelity RANS defines the 3D airfoil geometry. In order to accelerate the entire design procedure, a special routine was developed to morph the 1D results into the required info for the 3D optimization. Both the 1D and 3D optimizations are based on differential evolution algorithm.

Towards a High Order Throughflow: Part II—Investigation of the Nonlinear Harmonic Method Coupled With an Immersed Boundary Method for the Modeling of the Circumferential Stresses

2010 ◽  
Author(s):  
J. P. Thomas ◽  
O. Le´onard
Keyword(s):  
Immersed Boundary Method ◽  
Computational Cost ◽  
Inviscid Flow ◽  
Meridional Flow ◽  
Immersed Boundary ◽  
Harmonic Method ◽  
Boundary Method ◽  
Multi Stage ◽  
Through Flow ◽  
Second Category

Capturing a level of modeling of the flow inside a multi-stage turbomachine, such as unsteadiness for example, can be done at different degrees of details, either by capturing all deterministic features of the flow with a pure unsteady method or by settling for an approximated solution at a lower computational cost. The harmonic methods stand in this second category. Amongst them the “Nonlinear Harmonic Method” from He revealed the most efficient. This method consists of solving the fully nonlinear 3D steady problem and a linearized perturbation system in the frequency domain. As it has been shown by the authors that the circumferential variations exhibit a harmonic behavior, it is proposed here to adapt this method to the through-flow model, where the main nonlinear system would be the common throughflow equations and the auxiliary system would give access to the circumferential stresses. As the numerical local explicit impermeability conditions are unsupported by Fourier series, the adaptation of this technique to the throughflow model passes through a reformulation of the blade effect by a smooth force field as in the “Immersed Boundary Method” from Peskin. A simple example of an inviscid flow around a cylinder will illustrate the preceding developments, bringing back the mean effect of the circumferential non uniformities into the meridional flow.

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