Numerical and Experimental Results From a Common-Source High-G Ultra-Compact Combustor

Cottle, Andrew; Polanka, Marc D.

doi:10.1115/gt2016-56215

Cited by 9 publications

(3 citation statements)

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“…The remainder of the computational setup was based on previous works by Bohan, 28 Liu, 30 Cottle, 33 and others, who all performed experimental investigations for comparison with simulation results; these were used to validate the CFD computational setup for the turbulent combustion of the HGC. The realizable k –ε model was selected for the turbulence model.…”

Section: Methodsmentioning

confidence: 99%

Gear-Shaped High-g Combustion Chamber for Micro Turbojet Engine Applications

Huang,

Chen,

long

et al. 2024

ACS Omega

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Enhancing combustion efficiency and optimizing the thrust-toweight ratio are critical technical challenges encountered in the development, application, and growth of micro turbojet engines. The high-centrifugal (high-g) combustion chamber, as an innovative combustion chamber system, has the capability to replace the primary combustion chamber of the traditional turbojet engine, reducing the length of the combustion chamber while maintaining engine performance. Previous studies on the structure of the high-g combustor (HGC) have shown problems such as uneven temperature distribution of the turbojet rotor. To improve the feasibility of HGC integration into micro turbojet engines, this study conducts relevant experiments on a 120 N thrust engine. Subsequently, the results of these experiments were used to analyze the structural design of HGC through a simulation approach. Including six main configurations, the first four structural designs focused on establishing a suitable highly centrifugal environment to stabilize and improve the combustion performance, which was successfully achieved by designing the outer ring gearshaped inlet with four different angles. Subsequent structural designs were based around improving the uniformity of the temperature distribution at the combustion chamber outlet. The final design of the HGC combustion efficiency is not much different from the original combustion chamber, and it can shorten the axial length of the combustion chamber by nearly 30%. The design of the air inlet holes and the baffle plate effectively improves the temperature uniformity at the outlet of the combustion chamber. Moreover, without changing the combustion chamber material, the corresponding engine weight can be reduced by about 10.7%, and the engine thrust-to-weight ratio can be improved by up to 12% with the same thrust, which provides design ideas for further lightweight applications.

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Section: Methodsmentioning

confidence: 99%

Gear-Shaped High-g Combustion Chamber for Micro Turbojet Engine Applications

Huang,

Chen,

long

et al. 2024

ACS Omega

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“…On top of that, the reheat concept increases the flexibility of the combustion system by allowing the adjustment of the relative fuel load between the two combustors. Other studies include introduction and investigation of the Inter-Turbine Burner (ITB) by Sirignano and coworkers 11,12 and Ultra-Compact Combustor (UCC) by Zelina et al 13 and Cottle and Polanka 14 which bring the combustion process along the axial turbine stages. Pellegrini et al 15 presented an analytical methodology to study a gas turbine with Inter-stage Turbine Reheat (ITR) at design and offdesign modes.…”

Section: Introductionmentioning

confidence: 99%

The ultra-high efficiency gas turbine engine, UHEGT, Part II: A numerical study on reducing the stator blade surface temperature by indexing fuel injectors and using film cooling

Ghoreyshi

Schobeiri

2020

Proceedings of the Institution of Mechanical Engineers, Part A:

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In the Ultra-High Efficiency Gas Turbine Engine, UHEGT (introduced in our previous studies) the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed within the axial gaps before each stator row. This technology substantially increases the thermal efficiency of the engine cycle to above 45%, increases power output, and reduces turbine inlet temperature. Since the combustion process is brought into the turbine stages in UHEGT, the stator blades are exposed to high-temperature gases and can be overheated. To address this issue and reduce the temperature on the stator blade surface, two different approaches are investigated in this paper. The first is indexing (clocking) of the fuel injectors (cylindrical tubes extended from hub to shroud), in which the positions of the injectors are adjusted relative to each other and the stator blades. The second is film cooling, in which cooling holes are placed on the blade surface to bring down the temperature via coolant injection. Four configurations are designed and studied via computational fluid dynamics (CFD) to evaluate the effectiveness of the two approaches. Stator blade surface temperature (as the main objective function) along with other performance parameters such as temperature non-uniformity at rotor inlet, total pressure loss over the injectors, and total power production by rotor are evaluated for all configurations. The results show that indexing presents the most promising approach in reducing the stator blade surface temperature while producing the least amount of total pressure loss.

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“…Such a configuration in which a non-premixed fuel and oxidizer interface is subjected to high g-loading (∼ 300g 0 -3000g 0 ) is susceptible to the development of the RT instability at the flame site. RT instability is also influential in premixed formulations of the UCC concept, where pressure waves generated from ignition can accelerate the flamefront resulting in an increase in the flamespeed [119].…”

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confidence: 99%