Impact of hydrogen addition on combustion characteristics in a swirl-stabilized partially premixed combustor

Abstract

In today's world, rapidly increasing energy demand brings along significant challenges such as environmental pollution and inadequacy of energy resources. This situation necessitates a reevaluation of current energy production methods and the exploration of sustainable alternatives. Hydrogen is a crucial energy source that is at the forefront of these research efforts. The environmental impact and limited resources of hydrocarbon fuels have increased technological interest in the use of hydrogen in the aviation sector. The utilization of hydrogen in aviation propulsion systems has become a significant research area due to reasons such as environmental sustainability and efficiency advantages. The wide flammability range, high energy density, and high laminar flame speed of hydrogen present significant potential for efficiency and performance in the aviation industry. Additionally, hydrogen's clean energy source nature is a critical factor in achieving sustainability goals in the aviation industry. For these reasons, conducting experimental and numerical studies and ensuring technological advancements for the use of hydrogen in gas turbine engines in aviation are of great importance. Gas turbine engines are widely used technology for energy and thrust production, typically fueled by hydrocarbon fuels. Recent scientific research has shown that partially premixed methods can provide higher efficiency and lower emission values in gas turbine engines. Partially premixed combustion is a combustion method where a limited amount of air is mixed with the fuel before entering the combustor. This method enhances combustion efficiency and helps reduce emission levels, enabling more efficient fuel utilization and emission reduction. In the design of propulsion systems, numerical studies have gained importance alongside experimental research, thanks to the increasing computational resources. Nowadays, numerical studies conducted using computational fluid dynamics (CFD) methods have become a valuable tool in investigating aviation propulsion systems. This approach overcomes the cost and safety issues associated with experimental studies. The commonly used CFD methods include Reynolds-averaged Navier-Stokes (RANS), large eddy simulation (LES), and direct numerical simulation (DNS). DNS, due to its high computational cost and memory requirements for combustion problems, is currently not feasible. However, RANS and LES methods are more computationally affordable and are frequently preferred in the numerical studies. In particular, the LES method allows for larger-scale and more detailed analyses to be conducted.