- Design of a 3 Stage Axial LP Turbine for Aeroengine Applications
- Design of an Automobile Torque Converter
- Design High Performance Centrifugal Compressor Vaned Diffusers
- Redesign of an Industrial Compressor Stage
- Design of an Inducer Pump with High Suction Performance and Backflow Control
- Design High Efficiency Impellers with Splitter Blades
- Design High Performance Centrifugal Compressor Impellers
- Design of High Performance Pump Stage
- Design Optimisation of a Strongly Interacting Diffuser Pump Stage
- Design of a Cooling Fan
- Design of a Double-Suction Fan Stage
- Design of a Double-Suction Volute Pump
- Design of Refrigeration Compressor Stage in R134a
- Multi-Objective Optimisation of a Centrifugal Pump Stage by Means of Design of Experiment Coupled with Inverse Design Method
- Hydraulic Design Optimisation of a Torque Converter
- Suppression of Secondary Flows in a Turbine Nozzle with Controlled Stacking Shape and Exit Circulation by 3D Inverse Design Method
- An Inverse Design Based Methodology for Rapid 3D Multi-Objective / Multi-Disciplinary Optimisation of Axial Turbines
- Application of Simulated Annealing to Inverse Design of Transonic Turbomachinery Cascades
- On the Role of Three-Dimensional Inverse Design Methods in Turbomachinery Shape Optimization
- Investigation of an Inversely Designed Centrifugal Compressor Stage - Part II: Experimental Investigations
- TURBOdesign1 is Extensively Used at Voith Turbo for the Design of Hydrodynamic Torque Converters
- Inverse Design of Aeronautical Turbines in Avio S.p.A Design Process
- Application of TURBOdesign1 to the Development of an In-line Type Hydraulic Turbine for Micro Power Generation - KUBOTA
- Development of New Vertical Line Shaft Pumps
- Design of a Second Stage Hydrogen Rocket Turbopump by TURBOdesign1
Design High Performance Axial Turbine Stages with More Uniform Exit Flow
Blade lean is commonly used in the design of axial turbine nozzles to reduce endwall losses and to obtain a more uniform exit flow distribution. Numerical and experimental investigations have shown that the use of blade lean, whether straight or curved, in the conventional design practice merely redistributes the losses in the blade and does not result in a reduction in loss. This is partly because in conventional design the blade profile is kept the same and the stacking line is changed to achieve the blade lean. This can adversely affect the blade circulation distribution.
Fig.2: Stream lines near the endwall and exit loss contour of the nozzle with conventional radial stacking.
In TURBOdesign1 the blade profile is computed for a specified blade loading (and therefore circulation) distribution together with a specified thickness distribution and stacking condition. So the designer can change the blade stacking without any adverse effect on the blade circulation, as this is kept fixed. In order to demonstrate this fact, the blade loading shown in Figure 5, was used to design a nozzle. In the first instance radial stacking was used and the resulting blade geometry is shown in Figure 1. While keeping the same blade loading and thickness distributions the stacking condition was changed at both endwalls to reduce secondary flows. The resulting blade geometry computed by TURBOdesign1 can be seen in Figure 3.
Fig.6: Comparison of predicted exit stagnation pressure loss distribution for the radial and endwall stacking designs.
It is clear from Figure 6 that endwall stacking has resulted in appreciable reduction in endwall losses. However, more significantly, the nozzle with endwall stacking shows a reduction in overall stagnation pressure loss. This is in contrast to the effect of blade lean in conventional design practice (Figure 7), where blade lean merely redistributes the losses without resulting in any significant reduction in overall losses.
In the case of axial turbine rotor it is less common to use blade lean to influence the flow field because of structural considerations. However, by using TURBOdesign1, a designer can easily control the three-dimensional flow field by specifying the appropriate blade loading distributions. An example of a blade loading distribution used in the design of the rotor is shown in Figure 8. Using this distribution the rotor blade geometry shown in Figure 9 was obtained.
The endwall stacking nozzle and the rotor blade have been manufactured. The performance of this stage was then measured in an experimental test facility. The resulting efficiency of the TURBOdesign1 stage was found to be 2.5% higher at the design point as compared to the corresponding State-of-the-Art conventional stage, with appreciable improvements at off-design conditions. One important feature of the TURBOdesign1 stage was the very good matching between the nozzle and the rotor.
Since TURBOdesign1 is based on a three-dimensional inverse design method, it can automatically design the two blade shapes to provide good stage matching.