Design of shock-free transonic flow in turboomachinery

by Helmut Sobieczky

Publisher: Naval Postgraduate School in Monterey, California

Written in English
Published: Pages: 34 Downloads: 989
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  • Transonic Aerodynamics,
  • Cascades (Fluid dynamics),
  • Turbomachines

About the Edition

A new design method for transonic flow in turbomachinery is described. The idea is based on the author"s previous experience with hodograph methods but carried out in physical space. If combined with a flow analysis code the new method can be used as a design/analysis tool. Results illustrating this procedure are given for two dimensional flow through cascades and past airfoils. Existing configurations can be made shock-free by computational modifications which are limited to that portion of the design shape which is wetted by supersonic flow.

Edition Notes

StatementHelmut Sobieczky
ContributionsNaval Postgraduate School (U.S.)
The Physical Object
Paginationv, 34 p. :
Number of Pages34
ID Numbers
Open LibraryOL25510683M

This paper presents a procedure to extend a recently developed fully three-dimensional inverse method for highly-loaded turbomachine blades into the transonic-flow regime. In this inverse method, the required three-dimensional blade profile to produce a prescribed swirl schedule is determined iteratively using the blade boundary conditions. In most turbomachinery design systems streamline curvature based throughflow calculations makes the backbone of aero design process. The fast, reliable and easy to understand solution is especially useful in performing several multistage design iterations in a short period of time. Multidisciplinary design optimization (MDO) has been previously applied to aerostructural wing design problems with great success. Most previous applications involve fine-tuning a well-designed aircraft wing. In this work, we broaden the scope of the optimization problem by exploring the design space of aerostructural wing design optimization. (source: Nielsen Book Data) Summary Provides readers with an understanding of aerodynamic design and performance of fans and compressors. The book includes practical emphasis on design problems, experimental facilities and data analysis, together with some design examples and novel concepts. (source: Nielsen Book Data).

@article{osti_, title = {The design, performance and analysis of a high work capacity transonic turbine}, author = {Bryce, J D and Leversuch, N P and Litchfield, M R}, abstractNote = {This paper describes the design and testing of a high work capacity single-stage transonic turbine of aerodynamic duty tailored to the requirements of driving the high-pressure core of a low cost turbofan. The process was applied to two different transonic tan designs - the Sanger rotor designed for the NPS Turbomachinery Laboratory and NASA Ro otherwise known as the 'NASA Fan'. The optimization objectives for the two designs were mass flow rate and polytropic efficiency respectively. Cascade overall performance, blade-surface-pressure-distributions and flow-visualization are presented. The obtained results show that the blade shape has a strong influence on the loss behavior especially at off design conditions and on the shock system influencing the whole flow field of the blade row. Two reversible pump-turbine model runners, one with big positive and one with a big negative blade lean are investigated in experimental measurements and numerical simulations. The results offer guidance to reduce the pressure fluctuations in the pump-turbines while maintaining higher efficiency.

  The Prediction of 3D Transonic Flow in Turbomachinery Using a Combined Throughflow and Blade-to-Blade Time Marching Method A. Spurrt SUMMARY A new throughflow calculation method using the time marching numerical technique is presented and compared with other prediction methods for a low hub: tip radius ratio transonic nozzle. This paper summarizes the research on transonic turbine vane wake flows carried out in a Transonic Planar Cascade at the National Research Council of Canada between and The cascade used in the research is a large scale, continuously operating, inflow facility which was developed to study both flow phenomena and aerodynamics of. The compressor geometry chosen for this study has design characteristics of a transonic compressor stage. Flow field solutions were derived for baseline model by solving steady state 3-D Reynolds-Averaged Navier-Stokes (RANS) equations for three grid .   Caspar, JR. "Unconditionally Stable Calculation of Transonic Potential Flow Through Cascades Using an Adaptive Mesh for Shock Capture." Proceedings of the ASME International Gas Turbine Conference and Exhibit.

Design of shock-free transonic flow in turboomachinery by Helmut Sobieczky Download PDF EPUB FB2

An illustration of an open book. Books. An illustration of two cells of a film strip. Video. An illustration of an audio speaker. Audio. An illustration of a " floppy disk. Design of shock-free transonic flow in turboomachinery Item Preview remove-circle Share or Embed This : The method was validated and applied to the design of both two- and three-dimensional turbomachinery cascades in transonic flow, where it was demonstrated that the design.

Transonic flow computations using nonlinear potential methods. Progress in Aerospace Sciences, Vol. 36, No. Airfoil Design for Helicopter Rotor Blades - A Three-Dimensional Approach. Shock-free turbomachinery blade design. Philip Paul Beauchamp and Cited by: A challenging task of inducer design especially in terms of transonic inflow conditions is to provide a wide flow range and reduced losses due to a sufficient shock control.

The use of so called multidisciplinary design optimization with an extensive amount of free parameters leads finally to complex designs. The second test case is a highly-loaded gas turbine cascade operating in transonic flow at design and off-design conditions. This case is characterized by a normal shock appearing on the rear part of the blades’s suction surface, and is very sensitive to small changes in flow conditions.

A high flow coefficient centrifugal compressor was designed in a joint cooperation of DLR and MAN Diesel & Turbo SE Berlin. The main goal of this work is to increase the flow coefficient in the aerodynamic design point by 20% in comparison to the reference design.

Abstract. Many of the phenomena involved in turbomachinery flow can be understood and predicted on a two-dimensional (2D) or quasi-three-dimensional (Q3D) basis, but some aspects of the flow must be considered as fully three-dimensional (3D) and cannot be understood or predicted by the Q3D approach.

Arima, T, Sonoda, T, Shirotori, M, & Yamaguchi, Y. "Computation of Subsonic and Transonic Compressor Rotor Flow Taking Account of Reynolds Stress Anisotropy." Proceedings of the ASME International Gas Turbine and Aeroengine Congress and Exhibition.

Volume 1: Turbomachinery. Stockholm, Sweden. June 2–5, VT01A ASME. Prediction of boundary-layer transition is important to turbomachine design. Various experimental correlations are still the most practical models used in engineering calculations.

In an acceleration or deceleration flow field, however, the predictions depend on the free-stream turbulence intensity incorporated in the correlations.

Inverse Design of Turbomachinery Blading for Arbitrary Blade Thickness in Three-Dimensional Transonic Flow GT A Numerical Investigation of Stator-Rotor Interaction Effects on Flow Field and Film Cooling Effectiveness in a 3D Transonic Turbine Stage With Highly Twisted Rotors.

User Tools. Cart. Sign In. This post will remind you again that the meanline design step is one of the most important and the most critical ones in the whole aerodynamic design process of turbomachinery. When axial-flow (reaction) turbines are to be designed, there should be another check point in addition to a positive hub reaction (mentioned in MATADS ver A calculation system has been set up to predict both the internal flow field and the overall performance of a transonic compressor blade row.

The system iterates between an inviscid-viscous time-marching blade-to-blade (S1) treatment and a streamline curvature throughflow calculation for the pitchwise-averaged flow in the meridional plane (S2). TURBOdesign2 is an Aero/Hydro-dynamic design software for turbomachinery blades based on a 3D viscous transonic inverse design method.

It was developed mainly for the design of turbomachinery components such as transonic fans where shock/boundary layer interaction effects are significant.

A blade design procedure using an inviscid inverse method and a boundary layer calculation method is described and applied to the design of a shock free transonic compressor cascade.

The iterative character of the procedure provides a blade shape control good enough to design sufficiently thick blades resulting in realistic geometries. Motallebi, F, Edwards, SJ, & Norbury, JF.

"Base Pressure on a Blunt Base in Transonic Flow: Some Effects of Base Geometry and Bleed Air." Proceedings of the ASME International Gas Turbine Conference and Exhibit. Inverse Design of Turbomachinery Blading for Arbitrary Blade Thickness in Three-Dimensional Transonic Flow GT Computation of the Unsteady Transonic Flow in Harmonically Oscillating Turbine Cascades Taking Into Account Viscous Effects.

Purchase Transonic, Shock, and Multidimensional Flows - 1st Edition. Print Book & E-Book. ISBNThis paper presents a focusing schlieren system designed for the investigation of transonic turbine tip-leakage flows.

In the first part, the functional principle and the design of the system are presented. Major design considerations and necessary trade-offs are discussed. The key optical properties, e.g., depth of focus, are verified by means of a simple bench test.

A computer code that generates shock-free transonic compressor cascade shapes while taking into account viscosity effects is developed. The mathematical model for the inviscid flow field is the full potential equation.

The Kutta-Joukowski condition is satisfied by varying the free stream angle at downstream infinity. A multi-domain approach is used to handle difficulties due to the geometry of the flow.

An H-C grid was used in the calculations. Two turbulence models, based on the mixing length approach, were used. The flow in a transonic compressor cascade, a subsonic and a transonic turbine cascade were computed.

Comparison with experiments is presented. Transonic axial-flow compressors are used to obtain relatively high pressure ratios within a single stage. This reduces weight and size and offers a compact design. However, the transonic flow is sensitive to the profile shape and design of rotating and static components.

Another important factor is rotor stability when approaching stall conditions. In recent years, the growth in. TURBOdesign1. TURBOdesign1 is an inviscid aero/hydrodynamic design software for turbomachinery blades based on a 3D inverse design method. The code is applicable to all types of turbomachinery such as fans, pumps, compressors, turbines and torque converters in axial, mixed-flow.

König, WM, Hennecke, DK, & Fottner, L. "Improved Blade Profile Loss and Deviation Angle Models for Advanced Transonic Compressor Bladings: Part I — A Model for Subsonic Flow." Proceedings of the ASME International Gas Turbine and Aeroengine Congress and Exposition.

Volume 1: Turbomachinery. The Hague, Netherlands. June 13–16, The transonic flow regime is of critical practical interest in view of the desire to be able to design vehicles that can cruise efficiently at these speeds. Frequently, the transonic regime is also critical in regard to loading, stability and control, and flutter for vehicles that have to traverse this regime to achieve some desired higher.

My library Help Advanced Book Search. Computational Fluid Dynamics CFD is now an essential and effective tool used in the design of all types of turbomachine, and this topic constitutes the main theme of this book. Aerothermodynamics of turbomachinery: analysis and design / Naixing Chen – Details – Trove.

A transonic stall flutter occurs in high loaded condition at part rotating speed. A region of the transonic stall flutter occasionally protrudes to an operating line at narrow rotational speed range. This protrusion of flutter boundary is called flutter bite.

In that case, it is necessary to re-design the blade for securing sufficient operating. A new design method for transonic flow in turbomachinery is described. The idea is based on the author's previous experience with hodograph methods but carried out in physical space.

If combined with a flow analysis code the new method can be used as a design/analysis tool. Summary. A survey is given on aerodynamic inverse solution activities by the authors in the Institute of Engineering Thermophysics.

The survey includes stream function(SF) method of two different kinds of stream surfaces, which are usually assumed for the design in turbomachinery, stream-function-coordinate(SFC) method for two-dimensional and three-dimensional flows, potential function(PF.

A research program was initiated to experimentally study the flow field in a transonic radial nozzle cascade. An air test rig with variable nozzle vanes, derived from an industrial radial inflow turbine, was used for the tests. In this rig no rotor was installed in order to study the flow in the nozzles without any influence of this element.

7. Transonic Aerodynamics of Airfoils and Wings Introduction Transonic flow occurs when there is mixed sub- and supersonic local flow in the same flowfield (typically with freestream Mach numbers from M = or to ). Usually the supersonic region of the flow is terminated by a shock wave, allowing the flow to slow down to subsonic.At this condition, the Reynolds number based on outlet velocity is aboutOff-design outlet Mach numbers ofand were also investigated.

Flowfield measurements were carried out at 40% axial-chord downstream of the trailing edge, using a seven-hole pressure probe, to quantify losses and identify the flow structures.The flow through a transonic compressor cascade shows a very complex structure due to the occuring shock waves.

In addition, the interaction of these shock waves with the blade boundary layer inherently leads to a very unsteady flow behaviour.