Interactions of wakes and shock waves with two-phase air/mist cooling in a transonic gas turbine stage

2021 ◽  
Vol 179 ◽  
pp. 121652
Author(s):  
Ting Wang ◽  
Ramy Abdelmaksoud
Keyword(s):  
Shock Waves ◽  
Gas Turbine ◽  
Turbine Stage ◽  
Two Phase ◽  
And Shock Waves ◽  
Mist Cooling

Simulation of Air/Mist Cooling Among Shock Waves and Passing Wakes Interactions in a Transonic Gas Turbine Stage

2021 ◽  
Author(s):  
Ting Wang ◽  
Ramy Abdelmaksoud
Keyword(s):  
Shock Waves ◽  
Gas Turbine ◽  
Film Cooling ◽  
Suction Side ◽  
Water Droplets ◽  
Discrete Phase Model ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Cooling Enhancement ◽  
Mist Cooling

Abstract This paper presents a 2-D numerical investigation of the effect of interactions of moving wakes and shock waves on mist cooling performance over airfoils in the first stator-rotor stage of a transonic gas turbine. The discrete phase model (DPM) is used to simulate and track the evaporation and movement of the tiny water droplets. Breakup and coalescence sub-models are used to simulate the interaction between the droplets themselves. A linear sliding mesh technique is used to study the transient stator-rotor interaction. The results show that the passing unsteady wakes caused by the blade rotation press the mist on the blade suction side flowing near the blade surface, providing more enhanced film cooling effectiveness. The weak oblique shock waves do not exert a significant effect on the air/mist cooling effectiveness. Injecting a 10% mist ratio noticeably improved the cooling enhancement by reducing the wall temperature values up to 200 K in some locations. Injecting the tiny water droplets does not cause a noticeable pressure loss compared to the air-only cooling case. Injecting mist doesn’t alter the effect of shocks.

scholarly journals Simulation of Impinging Cooling Performance with Pin Fins and Mist Cooling Adopted in a Simplified Gas Turbine Transition Piece

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Tao Xu ◽  
Hang Xiu ◽  
Junlou Li ◽  
Haichao Ge ◽  
Qing Shao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Weighted Average ◽  
Two Phase ◽  
Cooling Performance ◽  
Pin Fin ◽  
Pin Fins ◽  
Mist Cooling ◽  
Transition Piece ◽  
Impinging Cooling

The gas turbine transition piece was simplified to a one-four cylinder double chamber model with a single row of impinging holes in the outer wall. Heat transfer augmentation in the coolant chamber was achieved through the use of pin fin structure and mist cooling, which could increase the turbulence and heat transfer efficiency. The present research is focused on heat transfer and pressure characteristics of the impinging cooling in the coolant chamber using FLUENT software. With the given diameter of impinging hole, pin fin diameter ratiosD/dhave been numerically studied in ranges from 1 to 2. Three different detachedLwere simulated. The impinging cooling performance in all cases was compared between single-phase and two-phase (imported appropriate mist) flow in the coolant chamber. All the simulation results reveal that the factors ofLandD/dhave significant effects on the convective heat transfer. After the pin fin structure was taken, the resulting temperature decrease of 38.77 K at most compared with the result of structure without pin fins. And with the mist injecting into the cooling chamber, the area weighted average temperature got a lower value without excess pressure loss, which could satisfy the more stringent requirements in engineering.

Design and Numerical Analysis of a Forepart Rotation Vane for a Variable Nozzle Turbine

2019 ◽  
Vol 36 (3) ◽  
pp. 233-244 ◽  
Author(s):  
Dengfeng Yang ◽  
Dazhong Lao ◽  
Ce Yang ◽  
Leon Hu ◽  
Harold Sun
Keyword(s):  
Numerical Analysis ◽  
Shock Waves ◽  
Flow Field ◽  
Rotor Blades ◽  
Leakage Flow ◽  
Exhaust Gas ◽  
Turbine Stage ◽  
And Shock Waves ◽  
Stage Performance ◽  
Stage Efficiency

AbstractThe influence of nozzle clearance on the flow field for a variable nozzle turbine, and moreover on the turbine stage performance was numerically investigated. Meanwhile, unsteady calculations were also performed to capture the shock waves which were induced by excessive acceleration of the exhaust gas. Aiming at improving the turbine stage performance and mitigating the shock waves, a forepart rotation vane was proposed and investigated in this work. The results indicated that by using the forepart rotation vane, the stage efficiency is increased by 6 % and the shock waves were eliminated successfully at small nozzle openings. Additionally, the intensity of pressure fluctuation that acts on the rotor blades was reduced by mitigation of clearance leakage flow and shock waves, which is beneficial for the reliability of rotor blades.

Features of spatial shock-wave flows in vapor-gas-liquid mixtures

2014 ◽  
Vol 10 ◽  
pp. 27-31
Author(s):  
R.Kh. Bolotnova ◽  
U.O. Agisheva ◽  
V.A. Buzina
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Shock Waves ◽  
Liquid Mixture ◽  
Liquid Mixtures ◽  
Pressure Vessels ◽  
Water Mixture ◽  
Two Dimensional ◽  
Nonstationary Processes ◽  
Two Phase

The two-phase model of vapor-gas-liquid medium in axisymmetric two-dimensional formulation, taking into account vaporization is constructed. The nonstationary processes of boiling vapor-water mixture outflow from high-pressure vessels as a result of depressurization are studied. The problems of shock waves action on filled by gas-liquid mixture volumes are solved.

Numerical investigation of non-uniform flow in twin-silo combustors and impact on axial turbine stage performance

2021 ◽  
pp. 095765092199394
Author(s):  
Hafiz M Hassan ◽  
Adeel Javed ◽  
Asif H Khoja ◽  
Majid Ali ◽  
Muhammad B Sajid
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Internal Flow ◽  
Large Temperature ◽  
Clear Understanding ◽  
Gas Temperature ◽  
Turbine Stage ◽  
Flow Angle ◽  
Axial Turbine ◽  
Stage Performance

A clear understanding of the flow characteristics in the older generation of industrial gas turbines operating with silo combustors is important for potential upgrades. Non-uniformities in the form of circumferential and radial variations in internal flow properties can have a significant impact on the gas turbine stage performance and durability. This paper presents a comprehensive study of the underlying internal flow features involved in the advent of non-uniformities from twin-silo combustors and their propagation through a single axial turbine stage of the Siemens v94.2 industrial gas turbine. Results indicate the formation of strong vortical structures alongside large temperature, pressure, velocity, and flow angle deviations that are mostly located in the top and bottom sections of the turbine stage caused by the excessive flow turning in the upstream tandem silo combustors. A favorable validation of the simulated exhaust gas temperature (EGT) profile is also achieved via comparison with the measured data. A drop in isentropic efficiency and power output equivalent to 2.28% points and 2.1 MW, respectively is observed at baseload compared to an ideal straight hot gas path reference case. Furthermore, the analysis of internal flow topography identifies the underperforming turbine blading due to the upstream non-uniformities. The findings not only have implications for the turbine aerothermodynamic design, but also the combustor layout from a repowering perspective.

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