The performance of the radial diffuser of a low pressure (LP) steam turbine is important to the power output of the turbine. A reliable and robust prediction and optimization tool is desirable in industry for preliminary design and performance evaluation. This is particularly critical during the tendering phase of retrofit projects, which typically cover a wide range of original equipment manufacturer and other original equipment manufacturers designs. This work describes a fast and reliable numerical approach for the simulation of flow in the last stage and radial diffuser coupled with the exhaust hood. The numerical solver is based on a streamline curvature throughflow method and a geometry-modification treatment has been developed for off-design conditions, at which large-scale flow separation may occur in the diffuser domain causing convergence difficulty. To take into account the effect of tip leakage jet flow, a boundary layer solver is coupled with the throughflow calculation to predict flow separation on the diffuser lip. The performance of the downstream exhaust hood is modeled by a hood loss model (HLM) that accounts for various loss generations along the flow paths. Furthermore, the solver is implemented in an optimization process. Both the diffuser lip and hub profiles can be quickly optimized, together or separately, to improve the design in the early tender phase. 3D computational fluid dynamics (CFD) simulations are used to validate the solver and the optimization process. The results show that the current method predicts the diffuser/exhaust hood performance within good agreement with the CFD calculation and the optimized diffuser profile improves the diffuser recovery over the datum design. The tool provides General Electric the capability to rapidly optimize and customize retrofit diffusers for each customer considering different constraints.
Skip Nav Destination
Article navigation
July 2017
Research-Article
Performance Prediction and Optimization of Low Pressure Steam Turbine Radial Diffuser at Design and Off-Design Conditions Using Streamline Curvature Method
David Karunakara
David Karunakara
Search for other works by this author on:
Luying Zhang
Francesco Congiu
Xiaopeng Gan
David Karunakara
1Corresponding author.
Contributed by the Turbomachinery Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received June 25, 2016; final manuscript received November 22, 2016; published online February 14, 2017. Editor: David Wisler.
J. Eng. Gas Turbines Power. Jul 2017, 139(7): 072601 (8 pages)
Published Online: February 14, 2017
Article history
Received:
June 25, 2016
Revised:
November 22, 2016
Citation
Zhang, L., Congiu, F., Gan, X., and Karunakara, D. (February 14, 2017). "Performance Prediction and Optimization of Low Pressure Steam Turbine Radial Diffuser at Design and Off-Design Conditions Using Streamline Curvature Method." ASME. J. Eng. Gas Turbines Power. July 2017; 139(7): 072601. https://doi.org/10.1115/1.4035527
Download citation file:
Get Email Alerts
Cited By
Image-based flashback detection in a hydrogen-fired gas turbine using a convolutional autoencoder
J. Eng. Gas Turbines Power
Fuel Thermal Management and Injector Part Design for LPBF Manufacturing
J. Eng. Gas Turbines Power
An investigation of a multi-injector, premix/micromix burner burning pure methane to pure hydrogen
J. Eng. Gas Turbines Power
Related Articles
Adjoint Method for Shape Optimization in Real-Gas Flow Applications
J. Eng. Gas Turbines Power (March,2015)
Design Optimization of a Wearable Artificial Pump-Lung Device With Computational Modeling
J. Med. Devices (September,2012)
Numerical Investigation of Heat Transfer in Turbine Cascades With Separated Flows
J. Turbomach (April,2003)
Related Proceedings Papers
Related Chapters
Other Components and Variations
Axial-Flow Compressors
Control and Operational Performance
Closed-Cycle Gas Turbines: Operating Experience and Future Potential
Aerodynamic Design and Performance Analysis of Exhaust Diffusers
Turbine Aerodynamics: Axial-Flow and Radial-Flow Turbine Design and Analysis