Accurate Inlet Boundary Conditions to Capture Combustion Chamber and Turbine Coupling With Large-Eddy Simulation

2021 ◽  
Author(s):  
Benjamin Martin ◽  
Florent Duchaine ◽  
Laurent Gicquel ◽  
Nicolas Odier ◽  
Jérôme Dombard
Keyword(s):  
Boundary Conditions ◽  
Combustion Chamber ◽  
Radial Profile ◽  
Point Of View ◽  
Interface Plane ◽  
Fully Integrated ◽  
Integrated Simulation ◽  
Eddy Simulation ◽  
Reconstructed Signal ◽  
Recorded Data

Abstract The coupling between different components of a turbomachinery is becoming more widely studied especially by use of Computational Fluid Dynamics. Such simulations are of particular interest especially at the interface between a combustion chamber and a turbine, for which the prediction of the migration of hotspots generated in the chamber is of paramount importance for performance and life-duration issues. Despite this need for fully integrated simulations, typical turbomachinery simulations however often only consider isolated components with either time-averaged constant value, radial profile or least frequently 2D maps imposed at their inlet boundaries preventing any accurate two-way coupling. The objective of the present study is to investigate available solutions to perform isolated simulations while taking into account the effect of multi-component coupling. Investigations presented in the paper focus on the FACTOR configuration. The fist step of the proposed method is to record conservative variables solved by the LES code at the interface plane between the chamber and the turbine of a reference simulation. Then, using the Spectral Proper Orthogonal Decomposition (SPOD) method, the recorded data is analysed and can be partially reconstructed using different numbers of frequencies. Using the partial reconstructions, it is then possible to replicate a realistic inlet boundary condition for isolated turbine simulations with both velocity and temperature fluctuations, while reducing the storage cost compared to the initial database. The integrated simulation is then compared to the isolated simulations as well as against simulations making use of averaged quantities with or without synthetic turbulence injection at their inlet. The isolated simulations for which the inlet condition is reconstructed with a large number of frequencies show very good agreement with the fully integrated simulation compared to the typical isolated simulation using average quantities at the inlet. As expected, decreasing the number of frequencies in the reconstructed signal deteriorates the accuracy of the resulting signal compared to the full recorded database. However, isolated simulations with a low number of frequencies still perform better than standard boundary conditions, especially from an aero-thermal point of view.

Accurate Inlet Boundary Conditions to Capture Combustion Chamber and Turbine Coupling with Large-Eddy Simulation

2021 ◽  
Author(s):  
Benjamin Martin ◽  
Florent Duchaine ◽  
Laurent Y.M. Gicquel ◽  
Nicolas Odier ◽  
Jerome Dombard
Keyword(s):  
Combustion Chamber ◽  
Interface Plane ◽  
Fully Integrated ◽  
Integrated Simulation ◽  
Eddy Simulation ◽  
Reference Simulation ◽  
Large Eddy ◽  
Recorded Data ◽  
Proper Orthogonal ◽  
Inlet Boundary Condition

Abstract The coupling between different components of a turbomachinery is becoming more widely studied especially by use of Computational Fluid Dynamics. Such simulations are of particular interest especially at the interface between a combustion chamber and a turbine, for which the prediction of the migration of hotspots generated in the chamber is of paramount importance for performance and life-duration issues. The objective of the present study is to investigate available solutions to perform isolated simulations while taking into account the effect of multi-component coupling. Investigations presented in the paper focus on the FACTOR configuration. The fist step of the proposed method is to record conservative variables solved by the LES code at the interface plane between the chamber and the turbine of a reference simulation. Then, using the Spectral Proper Orthogonal Decomposition method, the recorded data is analysed and can be partially reconstructed using different numbers of frequencies. Using the partial reconstructions, it is then possible to replicate a realistic inlet boundary condition for isolated turbine simulations with both velocity and temperature fluctuations, while reducing the storage cost compared to the initial database. The integrated simulation is then compared to the isolated simulations as well as against simulations making use of averaged quantities with or without synthetic turbulence injection at their inlet. The isolated simulations for which the inlet condition is reconstructed with a large number of frequencies show very good agreement with the fully integrated simulation compared to the typical isolated simulation using average quantities at the inlet.

scholarly journals Towards the Large-Eddy Simulation of a full engine: Integration of a 360 azimuthal degrees fan, compressor and combustion chamber. Part I: Methodology and initialisation

2021 ◽  
pp. 1-16
Author(s):  
Carlos Pérez Arroyo ◽  
Jérôme Dombard ◽  
Florent Duchaine ◽  
Laurent Gicquel ◽  
Benjamin Martin ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Combustion Chamber ◽  
Computational Cost ◽  
Thermodynamic Cycle ◽  
Turbine Engine ◽  
Fully Integrated ◽  
Integrated Simulation ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Impact

Optimising the design of aviation propulsion systems using computational fluid dynamics is essential to increase their efficiency and reduce pollutant as well as noise emissions. Nowadays, and within this optimisation and design phase, it is possible to perform meaningful unsteady computations of the various components of a gas-turbine engine. However, these simulations are often carried out independently of each other and only share averaged quantities at the interfaces minimising the impact and interactions between components. In contrast to the current state-of-the-art, this work presents a 360 azimuthal degrees large-eddy simulation with over 2100 million cells of the DGEN-380 demonstrator engine enclosing a fully integrated fan, compressor and annular combustion chamber at take-off conditions as a first step towards a high-fidelity simulation of the full engine. In order to carry such a challenging simulation and reduce the computational cost, the initial solution is interpolated from stand-alone sectoral simulations of each component. In terms of approach, the integrated mesh is generated in several steps to solve potential machine dependent memory limitations. It is then observed that the 360 degrees computation converges to an operating point with less than 0.5% difference in zero-dimensional values compared to the stand-alone simulations yielding an overall performance within 1% of the designed thermodynamic cycle. With the presented methodology, convergence and azimuthally decorrelated results are achieved for the integrated simulation after only 6 fan revolutions.

scholarly journals Generation of Realistic Boundary Conditions at the Combustion Chamber/Turbine Interface Using Large-Eddy Simulation

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8206
Author(s):  
Benjamin Martin ◽  
Florent Duchaine ◽  
Laurent Gicquel ◽  
Nicolas Odier
Keyword(s):  
Large Eddy Simulation ◽  
Boundary Conditions ◽  
Combustion Chamber ◽  
Important Criterion ◽  
Design Phase ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Cost ◽  
The Impact ◽  
Realistic Boundary Conditions

Numerical simulation of multiple components in turbomachinery applications is very CPU-demanding but remains necessary in the majority of cases to capture the proper coupling and a reliable flow prediction. During a design phase, the cost of simulation is, however, an important criterion which often defines the numerical methods to be used. In this context, the use of realistic boundary conditions capable of accurately reproducing the coupling between components is of great interest. With this in mind, this paper presents a method able to generate more realistic boundary conditions for isolated turbine large-eddy simulation (LES) while exploiting an available integrated combustion chamber/turbine LES. The unsteady boundary conditions to be used at the inflow of the isolated turbine LES are built from the modal decomposition of the database recorded at the interface between the two components of the integrated LES simulation. Given the reference LES database, the reconstructed field boundary conditions can then be compared to standard boundary conditions in the case of isolated turbine configuration flow predictions to illustrate the impact. The results demonstrate the capacity of this type of conditions to reproduce the coupling between the combustion chamber and the turbine when standard conditions cannot. The aerothermal predictions of the blade are, in particular, very satisfactory, which constitutes an important criterion for the adoption of such a method during a design phase.

scholarly journals Analysis of the Selected Parameters of the Thermal Reclaimer

2014 ◽  
Vol 14 (4) ◽  
pp. 67-72 ◽  
Author(s):  
M. Łucarz
Keyword(s):  
Heat Treatment ◽  
Combustion Chamber ◽  
Point Of View ◽  
Consumption Function ◽  
Temperature Changes ◽  
Treatment Processes ◽  
Energy Part ◽  
Gas Consumption ◽  
Recorded Data ◽  
Process Energy

Abstract The investigation results of the influence of the selected parameters of the thermal reclaimer operations on the temperature changes in the combustion chamber and the process energy consumption, are presented in the hereby paper. The analysis of the heat treatment was performed with the application of a fresh foundry sand, since it was assumed that the dominating energy part was used for the grain matrix heating and due to that, the energy used for burning small amounts of organic binder remained on sand grains could be omitted. Thermal treatment processes performed under various conditions were analysed from the point of view of a gas consumption and temperatures obtained in the experimental reclaimer. The recorded data allowed to point out the parameters having essential influence on the process of the quartz matrix heating in the combustion chamber as a gas consumption function.

Period equation for Rayleigh waves in a layer overlying a half space with a sinusoidal interface

1962 ◽  
Vol 52 (4) ◽  
pp. 807-822 ◽  
Author(s):  
John T. Kuo ◽  
John E. Nafe
Keyword(s):  
Wave Propagation ◽  
Boundary Conditions ◽  
Half Space ◽  
Rayleigh Waves ◽  
Wave Length ◽  
Linear Equations ◽  
Wave Number ◽  
Interface Plane ◽  
Period Equation ◽  
Phase And Group Velocities

abstract The problem of the Rayleigh wave propagation in a solid layer overlying a solid half space separated by a sinusoidal interface is investigated. The amplitude of the interface is assumed to be small in comparison to the average thickness of the layer or the wave length of the interface. Either by applying Rayleigh's approximate method or by perturbating the boundary conditions at the sinusoidal interface, plane wave solutions for the equations which satisfy the given boundary conditions are found to form a system of linear equations. These equations may be expressed in a determinant form. The period (or characteristic) equations for the first and second approximation of the wave number k are obtained. The phase and group velocities of Rayleigh waves in the present case depend upon both frequency and distance. At a given point on the surface, there is a local phase and local group velocity of Rayleigh waves that is independent of the direction of wave propagation.

Integrated Large Eddy Simulation of Combustor and Turbine Interactions: Effect of Turbine Stage Inlet Condition

2017 ◽  
Author(s):  
Florent Duchaine ◽  
Jérôme Dombard ◽  
Laurent Gicquel ◽  
Charlie Koupper
Keyword(s):  
Large Eddy Simulation ◽  
Combustion Chamber ◽  
Rotor Blade ◽  
Turbine Stage ◽  
High Pressure Turbine ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Stator Vane ◽  
Specific Configuration ◽  
Inlet Conditions

To study the effects of combustion chamber dynamics on a turbine stage aerodynamics and thermal loads, an integrated Large-Eddy Simulation of the FACTOR combustion chamber simulator along with its high pressure turbine stage is performed and compared to a standalone turbine stage computation operated under the same mean conditions. For this specific configuration, results illustrate that the aerodynamic expansion of the turbine stage is almost insensitive to the inlet turbulent conditions. However, the temperature distribution in the turbine passages as well as on the stator vane and rotor blade walls are highly impacted by these inlet conditions: underlying the importance of inlet conditions in turbine stage computations and the potential of integrated combustion chamber / turbine simulations in such a context.

Towards Improved Prediction of Aero-Engine Combustor Performance Using Large Eddy Simulations

2008 ◽  
Author(s):  
S. James ◽  
M. S. Anand ◽  
B. Sekar
Keyword(s):  
Gas Turbine ◽  
Radial Profile ◽  
Design Tool ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Gas Turbine Combustor ◽  
Systematic Assessment ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Aero Engine

The paper presents an assessment of large eddy simulation (LES) and conventional Reynolds averaged methods (RANS) for predicting aero-engine gas turbine combustor performance. The performance characteristic that is examined in detail is the radial burner outlet temperature (BOT) or fuel-air ratio profile. Several different combustor configurations, with variations in airflows, geometries, hole patterns and operating conditions are analyzed with both LES and RANS methods. It is seen that LES consistently produces a better match to radial profile as compared to RANS. To assess the predictive capability of LES as a design tool, pretest predictions of radial profile for a combustor configuration are also presented. Overall, the work presented indicates that LES is a more accurate tool and can be used with confidence to guide combustor design. This work is the first systematic assessment of LES versus RANS on industry-relevant aero-engine gas turbine combustors.

scholarly journals On Solutions of Fractional Order Boundary Value Problems with Integral Boundary Conditions in Banach Spaces

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Hussein A. H. Salem ◽  
Mieczysław Cichoń
Keyword(s):  
Boundary Conditions ◽  
Boundary Value Problems ◽  
Fractional Order ◽  
Nonlinear Term ◽  
Boundary Value ◽  
Nonlocal Boundary ◽  
Integral Boundary Conditions ◽  
Point Of View ◽  
Integral Boundary ◽  
Special Cases

The object of this paper is to investigate the existence of a class of solutions for some boundary value problems of fractional order with integral boundary conditions. The considered problems are very interesting and important from an application point of view. They include two, three, multipoint, and nonlocal boundary value problems as special cases. We stress on single and multivalued problems for which the nonlinear term is assumed only to be Pettis integrable and depends on the fractional derivative of an unknown function. Some investigations on fractional Pettis integrability for functions and multifunctions are also presented. An example illustrating the main result is given.

Sign in / Sign up

Export Citation Format

Share Document