Comparison of Labyrinth Seal Calculation and Real Aircraft Turbine Engine Measurement

2020 ◽  
Author(s):  
M. Čížek ◽  
T. Vampola ◽  
L. Popelka
Keyword(s):  
Labyrinth Seal ◽  
Turbine Engine

scholarly journals Advances in Abradable Coatings for Gas Turbines

1994 ◽  
Author(s):  
R. Schmid ◽  
A. R. Nicoll
Keyword(s):  
Gas Turbines ◽  
Environmental Changes ◽  
Labyrinth Seal ◽  
Operating Conditions ◽  
Mechanism Analysis ◽  
Coating Materials ◽  
Turbine Engine ◽  
Plasma Sprayed ◽  
Abradable Coatings ◽  
Sprayed Coatings

Gas turbine engine development continues to accelerate, creating more demanding requirements for abradable seal coatings. These coatings are necessary to provide very small clearances between the rotating and stationary parts in order to minimize gap losses and so Increase efficiency. The relatively few abradable coating materials developed over the last 20 years still perform well in many blade tip seal and labyrinth seal applications. However, rising operating temperatures, corrosion and other environmental changes, longer overhaul times and even better tip clearances are dictating the design of new coating materials which requires a strong scientific approach. For example, ways are being Investigated to replace Nickel-Graphite and other flame sprayed coatings being used between 450 and 700°C respectively because of steady state/corrosion/oxidation/erosion and wear problems respectively. New plasma and HVOF sprayed coatings have been developed using a systematic approach based on material response to operating conditions, minimizing trial and error. The major steps in the programme were: 1. Selection of constituent materials able to withstand service temperatures up to 325 (AISI-Polyester or Polyimide), 450 (AISI base), 700 (MCrAlY base) and 1100°C (ceramic base) respectively. 2. Powder particle manufacture and coating deposition to guarantee highly reproducible coatings. 3. Coating optimization based on wear tests carried out using a fully instrumented abradability test rig and wear mechanism analysis. 4. An investigation of blade tipping systems for high temperature applications. This paper discusses the results of plasma sprayed coatings developed for use at 450 and 700°C.

scholarly journals Aircraft Turbine Engine Labyrinth Seal CFD Sensitivity Analysis

2020 ◽  
Vol 10 (19) ◽  
pp. 6830
Author(s):  
Michal Čížek ◽  
Zdeněk Pátek ◽  
Tomáš Vampola
Keyword(s):  
Sensitivity Analysis ◽  
Aircraft Engine ◽  
Labyrinth Seal ◽  
Radial Clearance ◽  
Engineering Technology ◽  
Turbine Engine ◽  
Materials Engineering

This article presents the labyrinth seal radial clearance influence. A generic labyrinth seal of a turbine aircraft engine was modeled. The target is to compare and analyze the influence of the radial clearance and location of teeth. The results can be useful for designing the location of teeth and their appropriate setting, especially for materials engineering and engineering technology in general.

Advanced Seal Test Rig Validation and Operation

2006 ◽  
Author(s):  
Gerrit A. Kool ◽  
Arjen B. Kloosterman ◽  
Edward R. Rademaker ◽  
Bambang I. Soemarwoto ◽  
Fons M. G. Bingen ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
High Speed ◽  
High Surface ◽  
Weight Ratio ◽  
Labyrinth Seal ◽  
Test Rig ◽  
Turbine Engine ◽  
System A ◽  
Collaborative Program

Advanced seals have been identified as critical in meeting engine goals for specific fuel consumption, thrust-to-weight ratio, emissions, durability, and operating costs. In a direct effort to reduce the parasitic leakage, a high-temperature, high-speed seal test rig with Active Clearance Control (ACC) has been designed, built and validated by the National Aerospace Laboratory (NLR) in the Netherlands within a collaborative program with Sulzer Metco Turbine Components (SMTC) and Pratt & Whitney (P&W). NLR’s new seal test rig is capable to evaluate seals for the next generation gas turbine engines. It will test air seals (i.e., labyrinth, brush, and new seal concepts) in near gas turbine engine environment conditions of high temperature to 815 °C (1500 °F), high pressure to 2400 kPa (335 psid), high surface speeds to 365 m/s (1200 ft/s). Seal flows for typical engine seal clearances between 0.12 mm (0.005 inch) and 0.65 mm (0.025 inch) can be measured without changing test articles but by using the ACC system. A compressed air facility at the German-Dutch Windtunnel, located at the NLR site, delivers the required compressed clean and dry air. This paper describes the design, the instrumentation, the control system and the validation of the test rig. The rig certification was achieved by validating test measurements using a known three knife-edges stepped labyrinth seal. This paper also addresses the NLR’s CFD and engineering tool development to predict the seal performance.

Numerical Investigations for Leakage and Windage Heating in Straight-Through Labyrinth Seals

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Kali Charan Nayak ◽  
Pradip Dutta
Keyword(s):  
Cell Size ◽  
Turbulence Model ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Labyrinth Seal ◽  
Radial Clearance ◽  
Labyrinth Seals ◽  
Turbine Engine ◽  
Honeycomb Cell

The ability to quantify leakage flow and windage heating for labyrinth seals with honeycomb lands is critical in understanding gas turbine engine system performance and predicting its component life. Variety of labyrinth seal configurations (number of teeth, stepped or straight, honeycomb cell size) are in use in gas turbines, and for each configuration, there are many geometric factors that can impact a seal's leakage and windage characteristics. This paper describes the development of a numerical methodology aimed at studying the effect of honeycomb lands on leakage and windage heating. Specifically, a three-dimensional computational fluid dynamics (CFD) model is developed utilizing commercial finite volume-based software incorporating the renormalization group (RNG) k-ε turbulence model with modified Schmidt number. The modified turbulence model is benchmarked and fine-tuned based on several experiments. Using this model, a broad parametric study is conducted by varying honeycomb cell size, pressure ratio (PR), and radial clearance for a four-tooth straight-through labyrinth seal. The results show good agreement with available experimental data. They further indicate that larger honeycomb cells predict higher seal leakage and windage heating at tighter clearances compared to smaller honeycomb cells and smooth lands. However, at open seal clearances larger honeycomb cells have lower leakage compared to smaller honeycomb cells.

Effect of Rub-Grooves on Leakage and Windage Heating in Straight-Through Labyrinth Seals

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Kali Charan Nayak ◽  
Pradip Dutta
Keyword(s):  
Cell Size ◽  
Gas Turbines ◽  
Three Dimensional ◽  
Labyrinth Seal ◽  
Radial Clearance ◽  
Labyrinth Seals ◽  
Turbine Engine ◽  
Geometric Factors ◽  
Computational Fluid Dynamics Cfd ◽  
Honeycomb Cell

Prediction of leakage flow and windage heating for labyrinth seals with honeycomb lands is critical in understanding gas turbine engine system performance and predicting its component life. There are several labyrinth seal configurations in use in gas turbines, and for each configuration, there are many geometric factors that can impact a seal's leakage and windage characteristics. One of the factors which has not been thoroughly investigated in previously published work is the presence of rub-grooves in the honeycomb land and its impact on seal performance. This paper describes the development of a numerical methodology aimed at studying this effect. Specifically, a three-dimensional (3D) computational fluid dynamics (CFD) model is developed utilizing commercial finite volume-based software incorporating the renormalization group (RNG) k-ε turbulence model. Using this model, a broad parametric study is conducted by varying honeycomb cell size and radial clearance for a four-tooth straight-through labyrinth seal with and without rub-grooves. The results show good agreement with available experimental data. They further indicate that presence of rub-grooves increases seal leakage and decreases windage heating. The absolute levels depend on the clearance and honeycomb cell size.

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