A Turbomachinery Blade Design and Optimization Procedure

Author(s):  
C. Xu ◽  
R. S. Amano

With the development of the advanced technology, the combustion temperature is raised for increased efficiencies. At the same time, the turbine and compressor pressure ratio and the mass flow rate rise; thus causing turbine and compressor blades turning and blade lengths increase. Moreover, the high efficiency requirements had made the turbine and compressor blade design difficult. A turbine airfoil has been custom designed for many years, but an optimization for the section design in a three-dimensional consideration is still a challenge. For a compressor blade design, standard section cannot meet the modern compressor requirements. Modern compressor design has not only needs a custom designed section according to flow situation, but also needs three-dimensional optimizations. Therefore, a good blade design process is critical to the turbines and compressors. A blade design of the turbomachines is one of the important steps for a good turbomachine design. A blade design process not only directly influences the overall machine efficiency but also dramatically impact the design time and cost. In this study, a blade design and optimization procedure was proposed for both turbine and compressor blade design. A compressor blade design was used as a test case. It was shown that the current design process had more advantages than conventional design methodology.

Author(s):  
C. Xu ◽  
R. S. Amano

With the development of the advanced technology, the combustion temperature is raised for increased efficiencies. At the same time, the turbine and compressor pressure ratio and the mass flow rate rise; thus causing turbine and compressor blades turning and blade lengths increase. Moreover, the high efficiency requirements had made the turbine and compressor blade design difficult. A turbine airfoil has been custom designed for many years, but an optimization for the section design in a three-dimensional consideration is still a challenge. For a compressor blade design, standard section cannot meet the modern compressor requirements. Modern compressor design has not only needs a custom designed section according to flow situation, but also needs three-dimensional optimizations. Therefore, a good blade design process is critical to the turbines and compressors. A blade design of the turbomachines is one of the important steps for a good turbomachine design. A blade design process not only directly influences the overall machine efficiency but also dramatically impact the design time and cost. In this study, a blade design and optimization procedure was proposed for both turbine and compressor blade design. A compressor blade design was used as a test case. It was shown that the current design process had more advantages than conventional design methodology.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2401
Author(s):  
Weimin Song ◽  
Yufei Zhang ◽  
Haixin Chen

This paper focuses on the design and optimization of the axial distribution of the circumferential groove casing treatment (CGCT). Effects of the axial location of multiple casing grooves on the flow structures are numerically studied. Sweep and lean variations are then introduced to the blade tip, and their influences on the grooves are discussed. The results show that the ability of the CGCT to relieve the blockage varies with the distribution of grooves, and the three-dimensional blading affects the performance of both the blade and the CGCT. Accordingly, a multi-objective optimization combining the CGCT design with the sweep and lean design is conducted. Objectives, including the total pressure ratio and the adiabatic efficiency, are set at the design point; meanwhile, the choking mass flow and the near-stall performance are constrained. The coupling between the CGCT and the blade is improved, which contributes to an optimal design point performance and a sufficient stall margin. The sweep and lean in the tip redistribute the spanwise and chordwise loading, which enhances the ability of the CGCT to improve the blade’s performance. This work shows that the present CGCT-blade integrated optimization is a practical engineering strategy to develop the working capacity and efficiency of a compressor blade while achieving the stall margin extension.


Author(s):  
J. J. Waldren ◽  
C. J. Clark ◽  
S. D. Grimshaw ◽  
G. Pullan

Abstract Counter-rotating turbomachines have the potential to be high efficiency, high power density devices. Comparisons between conventional and counter-rotating turbomachines in the literature make multiple and often contradicting conclusions about their relative performance. By adopting appropriate non-dimensional parameters, based on relative blade speed, the design space of conventional machines can be extended to include those with counter-rotation. This allows engineers familiar with conventional turbomachinery to transfer their experience to counter-rotating machines. By matching appropriate non-dimensional parameters the loss mechanisms directly affected by counter-rotation can be determined. A series of computational studies are performed to investigate the relative performance of conventional and counter-rotating turbines with the same non-dimensional design parameters. Each study targets a specific loss source, highlighting which phenomena are directly due to counter-rotation and which are solely due to blade design. The studies range from two-dimensional blade sections to three-dimensional finite radius stages. It is shown that, at hub-to-tip ratios approaching unity, with matched non-dimensional design parameters, the stage efficiency and work output are identical for both types of machine. However, a counter-rotating turbine in the study is shown to have an efficiency advantage over a conventional machine of up to 0.35 percentage points for a hub-to-tip ratio of 0.65. This is due to differences in absolute velocity producing different spanwise blade designs.


2021 ◽  
pp. 1-24
Author(s):  
Venkatesh Suriyanarayanan ◽  
Quentin Rendu ◽  
Mehdi Vahdati ◽  
Loic Salles

Abstract This paper presents the effect of manufacturing tolerance on performance and stability boundaries of a transonic fan using a RANS simulation. The effect of tip gap and stagger angle was analysed through a series of single passage and double passage simulation; based on which an optimal arrangement was proposed for random tip gap and random stagger angle in case of a whole annulus rotor. All simulations were carried out using NASA rotor 67 as a test case and AU3D an in-house CFD solver. Results illustrate that the stagger angle mainly affects efficiency and hence its circumferential variation must be as smooth as possible. Furthermore, the tip gap affects the stability boundaries, pressure ratio and efficiency. Hence its optimal configuration mandates that the blades be configured in a zigzag arrangement around the annulus i.e. larger tip gap between two smaller ones.


Author(s):  
A. L. de Wet ◽  
T. W. von Backström ◽  
S. J. van der Spuy

The compressor section of a diesel locomotive turbocharger was re-designed to increase its maximum total-to-total pressure ratio and efficiency. Tests conducted on the prototype compressor showed possible rotating stall in the diffuser section before the designed higher pressure ratio could be achieved. It was decided to simulate the prototype compressor’s operation by using one-dimensional theory [1], followed by a three-dimensional CFD analysis of the compressor. This publication focuses on implementation of the impeller, vaneless annular passage and vaned diffuser one-dimensional theories. A verification process was followed to show the accuracy of the one- and three-dimensional modelling methods using two well-known centrifugal compressor test cases found in the literature [2–5]. Comparing the test case modelling results to available experimental results indicated sufficient accuracy to investigate the prototype compressor’s impeller and diffuser. Conclusions drawn on the prototype compressor’s performance using the one- and three-dimensional modelling methods led to a recommendation to redesign the impeller and diffuser of the prototype compressor.


Author(s):  
Richard J. Miller ◽  
Reginald D. Conner

The field validation and launch unit performance testing of a new high efficiency steam turbine design is described. The HEAT™ (High Efficiency Advanced Technology) steam turbine utilizes a new line of high efficiency steam path components developed by the author’s company [1], [2]. The extensive field test program, executed at the customer’s plant, included all major aspects of steam turbine operation and performance. Data was gathered continuously using multiple automated systems. Careful indexing of this data provided a multi-faceted view of operating phenomena during the test period. Overall machine performance was tested using ASME PTC 6.2 protocol. HP and IP individual section thermodynamic performance was quantified with a series of enthalpy drop tests. In addition, all leakage flows were measured to confirm end seal performance. HP section pressure ratio tests and internal leakage blowdown tests were done to determine the HP steam path aerodynamic characteristics. Various pressure measurements were used to quantify LP bucket aerodynamics and overall LP hood/diffuser performance. Validation testing of thermal-mechanical transient behavior of major components during all normal operating modes was achieved using lasers, thermocouples and strain gauges. In addition, thermal imaging was used to increase understanding of these transients. The validation instrumentation had an additional benefit to this customer, as it assisted the site team to successfully commission this A14 code type turbine, which achieved world-class efficiency.


Author(s):  
David Harper ◽  
Devin Martin ◽  
Harold Miller ◽  
Robert Grimley ◽  
Fre´de´ric Greiner

The MS6001C gas turbine combines the proven reliability of the General Electric gas turbine family with the advanced technology developed for the FA, FB and H machine designs. The engine configuration is a single shaft bolted rotor, driving a 50 or 60 Hz. generator though a cold end mounted load gear. Rated at 42.3 MW, with a thermal efficiency of 36.3%, the MS6001C will provide greater than a four percent increase in efficiency over the MS6001B. This paper is focused on the design and development of the MS6001C gas turbine, highlighting the commonality between this and other General Electric Power Systems (GEPS) and General Electric Aircraft Engines (GEAE) designs, as well as introducing some new and innovative features. The new high efficiency, 12 stage, axial flow compressor, features a 19:1 pressure ratio with three stages of variable guide vanes. The can annular, six chamber, Dry Low NOx (DLN-2.5H) combustion system is scaled from field proven, low emission technology. The turbine incorporates three stages, two cooled blade rows, and operates at a 1327°C firing temperature. After a thorough factory full speed no load test has been conducted, the first MS6001C engine will be shipped to a customer site in Kemalpasalzmir Turkey, where an instrumented full load test will be conducted to validate the design.


Author(s):  
Meijun Zhu ◽  
Lei Fu ◽  
Shuai Zhang ◽  
Yao Zheng

Three-dimensional supersonic nozzle is an important component of air-breathing hypersonic vehicles to produce thrust and lift force. Since the length of nozzle with ideal design is too long to meet the trim requirements of integrated air-breathing hypersonic vehicles, it is necessary to design a truncated nozzle to provide excellent aerodynamic performance. In the present study, an axisymmetric minimum length nozzle was firstly designed using method of characteristics. Then, streamlines trace technique with an offset circular entrance was adopted to extract the three-dimensional asymmetric nozzle. Nonlinear compression method was applied to compress the nozzle to a suitable length. Afterward, a surrogate-based optimization of three design variables, namely pressure ratio of nozzle’s exhaust to ambient, reserved initial expansion ratio, and average compression ratio was performed with the objectives of thrust and lift force, and a Pareto optimal front was therefore obtained. Numerical simulations were also made at six selected Pareto front cases to offer an insight into the flow fields. An infection point was observed in the Pareto front due to the maximum constrained length. The pressure ratio was found to be the most influential parameter, and the middle parts of Pareto front revealed better uniformity of exit flow.


2013 ◽  
Vol 135 (4) ◽  
Author(s):  
T. Korakianitis ◽  
M. A. Rezaienia ◽  
I. A. Hamakhan ◽  
A. P. S. Wheeler

The prescribed surface curvature distribution blade design (CIRCLE) method is presented for the design of two-dimensional (2D) and three-dimensional (3D) blades for axial compressors and turbines, and isolated blades or airfoils. The original axial turbine blade design method is improved, allowing it to use any leading-edge (LE) and trailing-edge (TE) shapes, such as circles and ellipses. The method to connect these LE and TE shapes to the remaining blade surfaces with curvature and slope of curvature continuity everywhere along the streamwise blade length, while concurrently overcoming the “wiggle” problems of higher-order polynomials is presented. This allows smooth surface pressure distributions, and easy integration of the CIRCLE method in heuristic blade-optimization methods. The method is further extended to 2D and 3D compressor blades and isolated airfoil geometries providing smooth variation of key blade parameters such as inlet and outlet flow angles, stagger angle, throat diameter, LE and TE radii, etc. from hub to tip. One sample 3D turbine blade geometry is presented. The efficacy of the method is examined by redesigning select blade geometries and numerically evaluating pressure-loss reduction at design and off-design conditions from the original blades: two typical 2D turbine blades; two typical 2D compressor blades; and one typical 2D isolated airfoil blade geometries are redesigned and evaluated with this method. Further extension of the method for centrifugal or mixed-flow impeller geometries is a coordinate transformation. It is concluded that the CIRCLE method is a robust tool for the design of high-efficiency turbomachinery blades.


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