Hari Priya Rajagopalan (Advisor: Prof. Timothy Charles Lieuwen)
will propose a doctoral thesis entitled,
Turbulent Burning Velocity of High H2 Fueled Premixed Flames
On
Friday, April 19 at 2:30 p.m. Montgomery Knight Building 317
Abstract
Hydrogen is being assessed as a potential energy carrier for a decarbonized energy economy. Utilization of H2 as a fuel in premixed gas turbine combustors substantially influences their fundamental combustion properties. Notably, the unstretched laminar propagation speed of hydrogen flames is four times higher than that of natural gas under equivalent adiabatic flame temperature conditions. Additionally, hydrogen (H2) exhibits significant effects on flashback propensity and turbulent flame propagation characteristics.
The turbulent burning velocity (ST) is one of the most important combustion properties controlling combustor operability limits, directly influencing blowoff, flashback, and combustion instabilities. Turbulence modifies the average conversion rate from premixed reactants to combustion products, a parameter measured by the turbulent global consumption speed (ST,GC). Despite extensive investigation through experimental, theoretical, and computational methods, there are still unresolved questions concerning the intricate interactions between turbulent flow fields and premixed flame chemistry.
In this proposed study, analysis of turbulent global consumption speeds (ST,GC) of lean high H2 flames will be conducted at gas turbine relevant pressures and preheat temperatures. The main motivation of this study is to assess some fundamental questions pertaining to turbulent flame speed correlations : (1) what is the appropriate laminar flame speed parameter to be utilized in the ST correlation and (2) how do the statistics of turbulence intensity impact the burning velocity at the flame leading edge. Turbulent flame properties such as the turbulent consumption speed (ST,GC) and the flame brush thickness (δFBT) will be computed using OH* chemiluminescence measurements in a high-pressure Bunsen burner facility. Following the measurements, we will perform investigations of the normalizing laminar flame speed parameter, employing data-driven approaches. Finally, flow characterization studies of these high Reynolds number turbulent flow fields will be undertaken to comprehend the impact of turbulent velocity statistics on flame propagation properties at the leading edge of the flame. We will conduct experiments using Laser Doppler velocimetry (LDV) technique to analyze single-point velocity statistics aimed at enhancing our understanding of this Reynolds number effect.
Committee
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Prof. Timothy Charles Lieuwen – School of Aerospace Engineering (advisor)
•
Prof. Adam Steinberg – School of Aerospace Engineering
•
Prof. P.K Yeung – School of Aerospace Engineering