Numerical Investigation of 100% Premixed Hydrogen Combustor at Gas Turbines Conditions Using Detailed Chemistry

2021 ◽  
Author(s):  
Sachin Menon ◽  
Thijs Bouten ◽  
Jan Withag ◽  
Sikke Klein ◽  
Arvind Gangoli Rao
Keyword(s):  
Numerical Investigation ◽  
Gas Turbines ◽  
Detailed Chemistry

Numerical Investigation on Cooling Air Flow and Resistance Characteristics Inner Laminated Cooling Structures

2019 ◽  
Author(s):  
Wei Song ◽  
Huazhao Xu ◽  
Xiaofang Cheng ◽  
Jianhua Wang
Keyword(s):  
Numerical Investigation ◽  
Flow Rate ◽  
Film Cooling ◽  
Gas Turbines ◽  
Flow Resistance ◽  
Resistance Coefficient ◽  
Inlet Velocity ◽  
Cooling Air ◽  
Laminated Structures ◽  
Simple Film

Abstract Today, laminated cooling structures have been widely used in the designs of advanced gas turbines, because the structures with double walls, pins, impingement holes and film holes can provide much higher overall cooling effectiveness than simple film cooling. Of course, this kind of cooling structures also leads to a higher price due to a larger flow resistance to cooling air injection in comparison with the simple film cooling. The previous investigations concerned with the laminated cooling structures mainly focused on heat transfer performances, the flow resistance characteristics within the complex channel of the structures are relatively less. This paper presents a numerical investigation on the characteristics of the cooling air resistance passing through 6 different laminated structures. The influence factors on the fluid flow and resistance performances of cooling air, such as array, density and shape of film hole, as well as impingement-hole area (diameter), are discussed and compared at the same pressure ratios of the inlet to outlet of the 6 laminated structures. The discussions and comparisons reveal the following interesting phenomena: 1) A larger diameter of impingement hole corresponds to a larger mass flow rate of cooling air at the inlet of the laminated structure, but the inlet velocity is mainly dependent on the density of film hole. At the same total area of film holes, a larger density corresponds to a higher inlet velocity. 2) The flow rate through film hole of laminated structures is influenced more and more obvious by the outlet shape and the inflow angle of film hole as the increasing pressure ratio. 3) The resistance coefficients of the entire laminated structures are dependent on the density and shape of film holes. At the same total area of film holes, a higher density corresponds to a lower resistance coefficient. Although fan-shaped film hole can provide a larger cooling air coverage, the price is a higher resistance coefficient. Therefore, the applications of fan-shaped film holes in the laminated structures should be considered only in the regions with low environment pressures.

Effect of Rotation on a Gas Turbine Blade Internal Cooling System: Numerical Investigation

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
E. Burberi ◽  
D. Massini ◽  
L. Cocchi ◽  
L. Mazzei ◽  
A. Andreini ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Internal Heat ◽  
Jet Impingement ◽  
Experimental Results ◽  
Inlet Temperature ◽  
Internal Cooling ◽  
Eddy Simulation

Increasing turbine inlet temperature is one of the main strategies used to accomplish the demand for increased performance of modern gas turbines. Thus, optimization of the cooling system is becoming of paramount importance in gas turbine development. Leading edge (LE) represents a critical part of cooled nozzles and blades, given the presence of the hot gases stagnation point, and the unfavorable geometrical characteristics for cooling purposes. This paper reports the results of a numerical investigation, carried out to support a parallel experimental campaign, aimed at assessing the rotation effects on the internal heat transfer coefficient (HTC) distribution in a realistic LE cooling system of a high pressure blade. Experiments were performed in static and rotating conditions replicating a typical range of jet Reynolds number (10,000–40,000) and Rotation number (0–0.05). The experimental results consist of flowfield measurements on several internal planes and HTC distributions on the LE internal surface. Hybrid RANS–large eddy simulation (LES) models were exploited for the simulations, such as scale adaptive simulation and detached eddy simulation, given their ability to resolve the complex flowfield associated with jet impingement. Numerical flowfield results are reported in terms of both jet velocity profiles and 2D vector plots on two internal planes, while the HTC distributions are presented as detailed 2D maps together with averaged Nusselt number profiles. A fairly good agreement with experiments is observed, which represents a validation of the adopted modeling strategy, allowing an in-depth interpretation of the experimental results.

Comparison of Combustion Models and Reaction Mechanisms for FLOX® Combustion

2009 ◽  
Author(s):  
Tobias Panne ◽  
Axel Widenhorn ◽  
Manfred Aigner
Keyword(s):  
Reaction Mechanisms ◽  
Gas Turbines ◽  
Combustion Model ◽  
Atmospheric Conditions ◽  
Flameless Combustion ◽  
High Pressure And Temperature ◽  
Detailed Chemistry ◽  
Ansys Cfx ◽  
Typical Operating Condition ◽  
Commercial Software Package

Flameless combustion is characterized by very low NOx and CO emissions. It has successfully been used in technical furnaces under atmospheric conditions for many years. For the use in modern gas turbines the combustors have to be redesigned to meet the typical operating condition, i.e. high pressure and temperature. The flameless combustion under gas turbine relevant conditions has successfully been simulated using a detailed chemistry model [1]. However computational costs and turnaround times are very high for these simulations. In this work the influence of different reduced reaction mechanisms on the heat release and on the temperature and flow field depending on the implied combustion model are investigated. As a benchmark the simulations are compared to experimental data obtained by OH* chemiluminescence and OH LIF measurements [2]. The simulations are performed on the basis of the commercial software package ANSYS CFX 11.0.

Performance Simulations of a Gas Turbine Disk-Blade Assembly Employing Miniature Radially Rotating Heat Pipes

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Yiding Cao ◽  
Jian Ling
Keyword(s):  
Heat Pipe ◽  
Numerical Investigation ◽  
Gas Turbines ◽  
Heat Pipes ◽  
Turbine Disk ◽  
Maximum Temperature ◽  
Material Strength ◽  
Inlet Temperature ◽  
Pipe Length ◽  
Blade Assembly

With a substantially increased gas inlet temperature in modern gas turbines, the cooling of turbine disks is becoming a challenging task. In order to reduce the temperature at the disk rim, a new turbine disk incorporating radially rotating heat pipes has been proposed. The objective of this paper is to conduct a numerical investigation for the cooling effectiveness of the rotating heat pipe. One of the major tasks of this paper is to compare the performance between a proposed disk-blade assembly incorporating radially rotating heat pipes and a conventional disk-blade assembly without the heat pipes under the same heating and cooling conditions. The numerical investigation illustrates that the turbine disk cooling technique incorporating radially rotating heat pipes is feasible. The maximum temperature at the rim of the proposed disk can be reduced by more than 100 °C in comparison with that of a conventional disk without heat pipes. However, the average temperature at the blade airfoil surface can be reduced by only about 10 °C. In addition, both the heat pipe length and diameter have an important effect on the turbine disk cooling. Under the permission of material strength, a longer heat pipe or a larger heat pipe diameter will produce a lower temperature at the disk rim.

scholarly journals Numerical Investigation of Oil Gas Separation with the Use of VOF CFD

2021 ◽  
Vol 11 (6) ◽  
pp. 7841-7845
Author(s):  
S. Tomescu ◽  
I. O. Bucur
Keyword(s):  
Porous Media ◽  
Numerical Investigation ◽  
Gas Turbines ◽  
Computer Aided Design ◽  
Volume Fraction ◽  
Numerical Study ◽  
Computational Domain ◽  
Two Phase ◽  
Volume Porosity ◽  
Set Up

In this research paper, a numerical study regarding gas-oil separation is presented. Employing the geometry of a classic separator used by the NRDI for Gas Turbines COMOTI and a Computer-Aided Design (CAD) software, the computational domain was defined. To perform the Computational Fluid Dynamics (CFD) investigation, the mesh was created with the ANSYS Meshing tool, and the ANSYS CFX was employed as a solver. The computational domain was split into 5 subdomains, 3 were fluid and 2 were defined as porous media. The volume porosity, loss model, and permeability were set up. In terms of turbulence flow, the standard k–ε model was adopted. The results of the numerical calculations in terms of oil volume fraction and streamline profiles were used to analyze the separator configuration. The results show that the numerical investigation with the VOF (Volume of Fluid Method) - CFD model is capable of analyzing the performance of a two-phase separator equipped with two demisters-porous media.

Numerical investigation of the ignition and annihilation of CH4/N2/O2 mixtures under MILD operative conditions with detailed chemistry

2016 ◽  
Vol 21 (1) ◽  
pp. 120-136 ◽  
Author(s):  
Giancarlo Sorrentino ◽  
Mariarosaria de Joannon ◽  
Pino Sabia ◽  
Raffaele Ragucci ◽  
Antonio Cavaliere
Keyword(s):  
Numerical Investigation ◽  
Detailed Chemistry

Emission prediction in conceptual design of the aircraft engines using augmented CRN

2017 ◽  
Vol 121 (1241) ◽  
pp. 1005-1028 ◽  
Author(s):  
Z. Saboohi ◽  
F. Ommi
Keyword(s):  
Conceptual Design ◽  
Gas Turbines ◽  
Chemical Reactor ◽  
Aviation Fuel ◽  
Analytical Prediction ◽  
Design Phase ◽  
Detailed Chemistry ◽  
Chemical Reactor Network ◽  
Conceptual Design Phase ◽  
Reactor Network

ABSTRACTThe semi-analytical prediction of pollutants emissions from gas turbines in the conceptual design phase is addressed in this paper. The necessity of this work arose from an urgent need for a comprehensive model that can quickly provide data in the conceptual design phase. Based on the available inputs data in the initial phases of the design process, a chemical reactor network (CRN) is defined to model the combustion with a detailed chemistry. In this way, three different chemical mechanisms are studied for Jet-A aviation fuel. Furthermore, the droplet evaporation for liquid fuel and the non-uniformity in fuel-air mixture are modelled. The results of a developed augmented modelling tool are compared with the pollutants data of two annular engine's combustors. The CRN results have good agreement with the actual engine test rig emissions output. In conclusion, the augmented CRN has shown to be efficient in predicting engine emissions with a very short executing time (few seconds) using a small CPU requirement such as a personal computer.

Numerical Investigation of Entropy Noise and Its Acoustic Sources in Aero-Engines

2008 ◽  
Author(s):  
Bernd Mu¨hlbauer ◽  
Berthold Noll ◽  
Manfred Aigner
Keyword(s):  
Numerical Investigation ◽  
Gas Turbines ◽  
Pressure Fluctuations ◽  
Three Dimensional ◽  
Power Spectra ◽  
Noise Simulation ◽  
Standard Configuration ◽  
Acoustic Sources ◽  
Aero Engines ◽  
First Time

In the present work, the generation and propagation of entropy noise was simulated applying a compressible three dimensional URANS CFD approach. To this end, a test rig, the so-called Entropy Wave Generator (EWG) was modeled. The EWG implies a non-reactive tube flow where entropy modes are induced to the air flow by a heating module. The generated temperature nonuniformities are accelerated in a convergent-divergent nozzle and excite entropy noise. Simulation results of pressure fluctuations and power spectra in the standard configuration as well as simulations of different operating points of the EWG are in very good agreement with measurements. Additionally, entropy noise was deduced for realistic gas turbine conditions with calculated sound pressure level above 160 dB, which evidences the relevance of entropy noise in gas turbines. The numerical investigation is completed by the analysis of the acoustic sources. For this purpose the acoustic sources caused by the acceleration of density inhomogeneities suggested by Dowling [1] were calculated. Thus, for the first time a method is introduced to locate the acoustic sources of entropy noise in the acceleration region.

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