The Three-Dimensional Structure of Swirl-Stabilized Flames in a Lean Premixed Multinozzle Can Combustor

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Janith Samarasinghe ◽  
Stephen J. Peluso ◽  
Bryan D. Quay ◽  
Domenic A. Santavicca
Keyword(s):  
Gas Turbine ◽  
Tomographic Reconstruction ◽  
Flame Structure ◽  
Combustion Process ◽  
Three Dimensional ◽  
Static Stability ◽  
Dimensional Structure ◽  
Reconstruction Technique ◽  
Three Dimensional Structure ◽  
The Relationship

Flame structure can have a significant effect on a combustor's static stability (resistance to blowoff) and dynamic stability (combustion instability) and therefore is an important aspect of the combustion process that must be taken into account in the design of gas turbine combustors. While the relationship between flame structure and flame stability has been studied extensively in single-nozzle combustors, relatively few studies have been conducted in multinozzle combustor configurations typical of actual gas turbine combustion systems. In this paper, a chemiluminescence-based tomographic reconstruction technique is used to obtain three-dimensional images of the flame structure in a laboratory-scale five-nozzle can combustor. Analysis of the 3D images reveals features of the complex, three-dimensional structure of this multinozzle flame. Effects of interacting swirling flows, flame–flame interactions, and flame–wall interactions on the flame structure are also discussed.

The 3-D Structure of Swirl-Stabilized Flames in a Lean Premixed Multi-Nozzle Can Combustor

2015 ◽  
Author(s):  
Janith Samarasinghe ◽  
Stephen J. Peluso ◽  
Bryan D. Quay ◽  
Domenic A. Santavicca
Keyword(s):  
Gas Turbine ◽  
Tomographic Reconstruction ◽  
Flame Structure ◽  
Combustion Process ◽  
Three Dimensional ◽  
Static Stability ◽  
Dimensional Structure ◽  
Reconstruction Technique ◽  
Flame Stability ◽  
The Relationship

Flame structure is an important aspect of the combustion process which must be considered in the design of gas turbine combustors as it can have a significant effect on the combustor’s static stability (blowoff) and dynamic stability (combustion instability). The relationship between flame structure and flame stability has been studied extensively in single-nozzle combustors. However, relatively few studies have been conducted in multi-nozzle combustor configurations typical of actual gas turbine combustion systems. In this paper, a chemiluminescence-based tomographic reconstruction technique is used to obtain three-dimensional images of the flame structure in a laboratory-scale five-nozzle can combustor. The images reveal the complex three-dimensional structure of this multi-nozzle flame, as well as, the effects of interacting swirling flows, flame-flame interactions and flame-wall interactions on flame structure.

CFD Modeling of Flame Structures in a Gas Turbine Combustion Reactor: Velocity, Temperature, and Species Distribution

2017 ◽  
Vol 15 (4) ◽  
Author(s):  
Alireza Bahramian ◽  
Mozhdeh Maleki ◽  
Bijan Medi
Keyword(s):  
Temperature Profile ◽  
Gas Turbine ◽  
Cfd Simulation ◽  
Flame Structure ◽  
Combustion Process ◽  
Three Dimensional ◽  
Species Distributions ◽  
Kinetic Mechanism ◽  
Cfd Modeling ◽  
Laser Measurements

Abstract This paper presents the computational fluid dynamics (CFD) simulation of a gas turbine combustor with methane-air fuel at atmospheric pressure. The velocity fields, temperature profile and species distributions have been numerically studied. The mathematical combustion models, namely Eddy Dissipation Concept (EDC) model coupled with detailed kinetic mechanism, and Finite Rate/Eddy Dissipation (FR-ED) model coupled with a simple global kinetic mechanism, have been used in numerical analysis considering a two-step oxy-combustion reaction kinetics model. Moreover, a series of CFD results with consideration of EDC model have been obtained by two- and three-dimensional simulations. An error analysis showed that the 3-D simulation with EDC model can accurately predict the velocity components, temperature profile, and species distributions of the combustion process and allow detailed investigation of the flame structure. The CFD results are in agreement with the experimental data obtained from laser measurements.

scholarly journals Heavy rain and strong wind events and cyclones in the Balearics

2006 ◽  
Vol 7 ◽  
pp. 73-77 ◽  
Author(s):  
J. Campins ◽  
A. Jansà ◽  
A. Genovés
Keyword(s):  
Three Dimensional ◽  
Geographical Location ◽  
Heavy Rain ◽  
Balearic Islands ◽  
Dimensional Structure ◽  
Strong Wind ◽  
Affected Area ◽  
Three Dimensional Structure ◽  
Wind Events ◽  
The Relationship

Abstract. The relationship between heavy rain (HR) and/or strong wind (SW) events and cyclones is investigated for the Balearic Islands. First, a list of HR and SW events is cross-referenced with an objective cyclone database for a 9-year period (from June 1995 to May 2004). The presence of a cyclone centre close to the Balearics is looked for each event. For HR events in most of the cases a cyclone centre is located in the vicinity. Furthermore, cyclones are located in such a way that allow the supply of warm and wet air to the affected area. But for SW events, although in the majority of cases a cyclone centre is detected, cyclones are located farther than for HR events and their geographical location is more widespread. Afterwards, the three-dimensional structure of cyclones related to HR and/or SW events is studied in detail.

scholarly journals Optimal Growth in Inertia–Gravity Wave Packets: Energetics, Long-Term Development, and Three-Dimensional Structure

2006 ◽  
Vol 63 (2) ◽  
pp. 414-434 ◽  
Author(s):  
Ulrich Achatz ◽  
Gerhard Schmitz
Keyword(s):  
Gravity Wave ◽  
Normal Mode Analysis ◽  
Three Dimensional ◽  
Optimal Growth ◽  
Static Stability ◽  
Mode Analysis ◽  
Dimensional Structure ◽  
Linear Wave ◽  
Invariant Structure ◽  
Three Dimensional Structure

Abstract Using a hierarchy of three models of increasing realism and complexity, and expanding on a previous study, optimal perturbations of inertia–gravity wave (IGW) packets are studied with respect to several aspects. It is shown that normal modes are comparatively less able to extract energy from the IGW over finite time due to their time-invariant structure, while singular vectors (SVs) can adjust their dynamical fields flexibly so as to optimize the statically enhanced roll and Orr mechanisms by which they grow. On longer time scales, where the time dependence of the IGW packet precludes a normal-mode analysis, optimal growth is found to further amplify suitable perturbations. The propagation characteristics of these exhibit critical layer interactions for horizontal propagation directions transverse with respect to the IGW, preventing significant vertical propagation, while parallel and obliquely propagating perturbations of sufficiently long horizontal scales are found to radiate gravity waves into altitudes not directly affected by the IGW. The SVs with shorter wavelengths, as found for short optimization times, stay confined via a linear wave duct near the altitude of least static stability where they are excited. At optimization times of the order of the IGW period the leading SVs, with an energy growth by about three orders of magnitude, propagate obliquely, possibly in correspondence to previous results by others from simulations of nonlinear IGW breakdown. The three-dimensional structure of SVs shows an amplitude modulation strictly confining the perturbations also to the horizontal location of least static stability, suggesting a picture of turbulence onset in IGW packets where local patches of growing perturbations initially dominate.

Mutagenesis of squash (Cucurbita moschata) glycerol-3-phosphate acyltransferase (GPAT) to produce an enzyme with altered substrate selectivity

2000 ◽  
Vol 28 (6) ◽  
pp. 680-681 ◽  
Author(s):  
M. W. Hayman ◽  
T. Fawcett ◽  
T. F. Schierer ◽  
J. W. Simon ◽  
J. T. M. Kroon ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Recombinant Enzyme ◽  
Dimensional Structure ◽  
Substrate Selectivity ◽  
Cucurbita Moschata ◽  
Three Dimensional Structure ◽  
Overexpression System ◽  
The Relationship

In an attempt to rationalize the relationship between structure and substrate selectivity of glycerol-3-phosphate acyltransferase (GPAT, 1AT, EC 2.3.1.15) we have cloned a number of cDNAs into the PET overexpression system using a PCR-based approach. Following assay of the recombinant enzyme we noted that the substrate selectivity of the squash (Cucurbita moschata) enzyme had altered dramatically. This form of GPAT has now been crystallized and its full three-dimensional structure elucidated. Since we now have two forms of the enzyme that display different substrate selectivities this should provide a powerful tool to determine the basis of the selectivity changes. Kinetic and structural analyses are currently being performed to rationalize the changes which have taken place.

Sign in / Sign up

Export Citation Format

Share Document