scholarly journals Discussion: “A Quasi-Three-Dimensional Turbomachinery Blade Design System: Parts I and II” (Jennions, I. K., and Stow, P., 1985, ASME J. Eng. Gas Turbines Power, 107, pp. 301–314)

1985 ◽  
Vol 107 (2) ◽  
pp. 314-315
Author(s):  
C. Hirsch
Author(s):  
Guy Phuong ◽  
Sylvester Abanteriba ◽  
Paul Haley ◽  
Philippe Guillerot

Volutes are widely used in centrifugal compressors for industrial processes, refrigeration systems, small gas turbines and gas pipelines. However, large costs associated with the volute design and analysis process can be reduced with the introduction of a software design system that ties together both geometry creation and mesh generation having the ultimate intent of improving stage efficiency. Computational Fluid Dynamics (CFD) has become an integral part of engineering design. High quality grids need to be produced as part of the analysis process. Engineers of different expertise may be required to determine volute design constraints and parameters, produce the geometry, and generate a high quality grid. The current research aims to develop and demonstrate a volute design tool that allows design engineers the ability to easily and efficiently generate volute geometry and automate grid generation by means of geometrical constraints using functional relationships. The approach was outlined in [1]. Visualization of volute geometry can be in two-dimensional (2D) or three-dimensional (3D) modes. Control of the diffuser upstream of the scroll, the scroll itself and the conic are totally integrated in the design system. The user can position the conic anywhere in space and control the shape of the conic centroid curve, therefore having complete control over the development of the tongue region. The program will output data for automated grid generation where user can control resulting grid properties. Once the desired design configuration has been determined, the users can output the geometry surfaces and wireframes to a Computer Aided Design (CAD) package for production. Every little detail is also incorporated into the software from volute draft angle, discharge conic centroid shape, to cross section fillet radii. Upon entering all the required constraints and parameters of the volute, the geometry is created in seconds. Grids can be generated in minutes accommodating geometrical changes thus reducing the bottlenecks associated with geometry/grid generation for CFD applications.


1985 ◽  
Vol 107 (2) ◽  
pp. 301-307 ◽  
Author(s):  
I. K. Jennions ◽  
P. Stow

The purpose of this work has been to develop a quasi-three-dimensional blade design and analysis system incorporating fully linked throughflow, blade-to-blade and blade section stacking programs. In Part I of the paper, the throughflow analysis is developed. This is based on a rigorous passage averaging technique to derive throughflow equations valid inside a blade row. The advantages of this approach are that the meridional streamsurface does not have to be of a prescribed shape, and by introducing density weighted averages the continuity equation is of an exact form. Included in the equations are the effects of blade blockage, blade forces, blade-to-blade variations and loss. The solution of the equations is developed for the well-known streamline curvature method, and the contributions from these extra effects on the radial equilibrium equation are discussed. Part II of the paper incorporates the analysis into a quasi-three-dimensional computing system and demonstrates its operational feasibility.


Author(s):  
Y. S. Li ◽  
R. G. Wells

This paper presents the aerodynamic design and initial test results from a three-stage transonic compressor developed by ALSTOM Gas Turbines Ltd. The Advanced Transonic Compressor (ATC) was designed using a design system based on three-dimensional (3D) Navier-Stokes CFD codes in contrast to the more conventional design approach centred around the use of throughflow and blade to blade solvers. The customised 3D multiple-circular-arc (MCA) and controlled-diffusion (CD) airfoils have replaced the double-circular-arc (DCA) profiles used previously. The use of both single row and multistage 3D CFD codes has enabled the potential performance improvements from the application of new blade designs to be predicted and comparisons between conventional and new blades to be made. Rig test results have confirmed that the target design mass flow rate and pressure ratio have been successfully achieved in the first build with a design point efficiency higher than that possible from the conventional design. Tests have demonstrated that the compressor has the required surge margin at design and off design speeds to ensure satisfactory operation when transferred to the multistage compressor environment.


Author(s):  
Xiying Niu ◽  
Feng Lin ◽  
Weiyan Xiao ◽  
Guoqiang Li ◽  
Chen Liang

A turbine aerodynamic optimization design system for marine gas turbines has been investigated to accelerate the turbine aerodynamic design process and perfect the research and development platform. The data can be conversed automatically with the self-compiling programs which integrate the 1D, S2 module of Concepts NREC, three dimensional modeling, analysis, and optimization of NUMECA. At the same time, the system can satisfy multilevel optimization design easily for different requirements. And the system has been used in the optimization design of a marine gas turbine. The results show that the design period can be reduced; after optimization the efficiency is improved about one percent; and the off-design performance is improved due to the rear loading technology.


1985 ◽  
Vol 107 (2) ◽  
pp. 308-314 ◽  
Author(s):  
I. K. Jennions ◽  
P. Stow

The purpose of this work has been to develop a quasi-three-dimensional blade design and analysis system. In Part II of the paper the computerized blade design system is presented and an example given to illustrate its use. The system comprises a streamline curvature throughflow program incorporating the analysis of Part I of this paper, a blade section stacking program, and one of a number of blade-to-blade calculation programs. The information flow between each part of the system is described and the importance of each stage in the calculation indicated. Information is transferred between programs via a data base which enables other design programs, e.g., heat transfer programs, to access the results. This modular approach enables individual design program advances to be made relatively easily. The system is flexible enough to incorporate a number of blade-to-blade programs, the one used depending on the specific application. An example of the flow through a turbine nozzle guide vane is presented. Experimental data are compared with the results from the quasi-three-dimensional system, a fully three-dimensional program and an unlinked two-dimensional system. The results from the quasi-three-dimensional system are very encouraging.


Author(s):  
Stephan Uhkoetter ◽  
Stefan aus der Wiesche ◽  
Michael Kursch ◽  
Christian Beck

The traditional method for hydrodynamic journal bearing analysis usually applies the lubrication theory based on the Reynolds equation and suitable empirical modifications to cover turbulence, heat transfer, and cavitation. In cases of complex bearing geometries for steam and heavy-duty gas turbines this approach has its obvious restrictions in regard to detail flow recirculation, mixing, mass balance, and filling level phenomena. These limitations could be circumvented by applying a computational fluid dynamics (CFD) approach resting closer to the fundamental physical laws. The present contribution reports about the state of the art of such a fully three-dimensional multiphase-flow CFD approach including cavitation and air entrainment for high-speed turbo-machinery journal bearings. It has been developed and validated using experimental data. Due to the high ambient shear rates in bearings, the multiphase-flow model for journal bearings requires substantial modifications in comparison to common two-phase flow simulations. Based on experimental data, it is found, that particular cavitation phenomena are essential for the understanding of steam and heavy-duty type gas turbine journal bearings.


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