Numerical simulation and experimental verification of gravity and centrifugal investment casting low pressure turbine blades for high Nb–TiAl alloy

The chemistry check-ups were reviewed in the first maintenance of 600 MW supercritical once-through boiler units in Henan. Several problems were found: (1) high rates of scaling on the waterwall and economizer; (2) high rates of salt deposition on the turbine blades; (3) the formation of salt deposits on blades were complicated; (4) corrosion of low pressure turbine blades in period of maintenance was a universal phenomenon; (5) FAC (flow-accelerated corrosion) were most frequent in HP heaters and HP drain lines in most fossil plants. The reasons have been analyzed and the suggestions have been provided.

Download Full-text

Ceramic shell moulds for investment casting of low-pressure turbine rotor blisk

Ceramics International ◽

10.1016/j.ceramint.2020.10.152 ◽

2020 ◽

Author(s):

Y. Venkat ◽

K.R. Choudary ◽

D.K. Das ◽

A.K. Pandey ◽

Sarabjit Singh

Keyword(s):

Investment Casting ◽

Low Pressure ◽

Turbine Rotor ◽

Ceramic Shell ◽

Low Pressure Turbine

Download Full-text

The Science, Technology, and Implementation of TiAl Alloys in Commercial Aircraft Engines

MRS Proceedings ◽

10.1557/opl.2013.44 ◽

2013 ◽

Vol 1516 ◽

pp. 49-58 ◽

Cited By ~ 85

Author(s):

B. P. Bewlay ◽

M. Weimer ◽

T. Kelly ◽

A. Suzuki ◽

P.R. Subramanian

Keyword(s):

Titanium Aluminide ◽

Turbine Blades ◽

Aircraft Engine ◽

Low Pressure ◽

Major Advance ◽

Commercial Aircraft ◽

Tial Alloys ◽

Low Pressure Turbine ◽

Titanium Aluminide Alloy ◽

History Of

ABSTRACTThe present article will describe the science and technology of titanium aluminide (TiAl) alloys and the engineering development of TiAl for commercial aircraft engine applications. The GEnxTM engine is the first commercial aircraft engine that is flying titanium aluminide (alloy 4822) blades and it represents a major advance in propulsion efficiency, realizing a 20% reduction in fuel consumption, a 50% reduction in noise, and an 80% reduction in NOx emissions compared with prior engines in its class. The GEnxTM uses the latest materials and design processes to reduce weight, improve performance, and reduce maintenance costs.GE’s TiAl low-pressure turbine blade production status will be discussed along with the history of implementation. In 2006, GE began to explore near net shape casting as an alternative to the initial overstock conventional gravity casting plus machining approach. To date, more than 40,000 TiAl low-pressure turbine blades have been manufactured for the GEnxTM 1B (Boeing 787) and the GEnxTM 2B (Boeing 747-8) applications. The implementation of TiAl in other GE and non-GE engines will also be discussed.

Download Full-text

Flutter Mechanisms in Low Pressure Turbine Blades

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education ◽

10.1115/98-gt-573 ◽

1998 ◽

Cited By ~ 8

Author(s):

M. Nowinski ◽

J. Panovsky

Keyword(s):

Research Effort ◽

Turbine Blades ◽

Low Pressure ◽

Design Parameters ◽

Computational Techniques ◽

Influence Coefficient ◽

Low Pressure Turbine ◽

Blade Flutter ◽

Euler Methods ◽

Annular Cascade

The work described in this paper is part of a comprehensive research effort aimed at eliminating the occurrence of low pressure turbine blade flutter in aircraft engines. The results of fundamental unsteady aerodynamic experiments conducted in an annular cascade are studied in order to improve the overall understanding of the flutter mechanism and to identify the key flutter parameters. In addition to the standard traveling wave tests, several other unique experiments are described. The influence coefficient technique is experimentally verified for this class of blades. The beneficial stabilizing effect of mistuning is also directly demonstrated. Finally, the key design parameters for flutter in low pressure turbine blades are identified. In addition to the experimental effort, correlating analyses utilizing linearized Euler methods demonstrate that these computational techniques are adequate to predict turbine flutter.

Download Full-text