Session: 01-06 Alternative Fuels in Whole Engine Performance

Paper Number: 153370

Investigation of Fuel Deposition in an Aviation Fuel Injector Under Controlled Conditions Using a Last-Chance Screen 

Aviation jet engines often encounter anomalies in the fuel injector systems that result in inefficiencies and lifetime reduction of the engine. One of the primary causes of such anomalies is the thermal degradation of the jet fuel when exposed to high temperatures. The consistency of fuel breakdown can lead to the formation of carbon deposits, which can cause significant blockage in various engine components, particularly in the fuel injector. Fuel deposition primarily occurs in the fuel nozzle passage, which can alter the spray distribution to the combustor and subsequently affect the efficiency of the combustion process. Hence, last-chance screens are often used to filter out unwanted solid particles. An experimental apparatus was developed to research occurrence and causes of the fuel breakdown, or coking, in a controlled environment. The ability to study the effects of flow rate, pressure, and temperature enhances our understanding of the chemical breakdown of fuel under conditions similar to those in an engine. The analysis consists of capturing the deposition, or solid “coke”, in a mesh where the measurement takes place. The experiment operates under a steady-state process, with variations in pressure and flow rates at a constant temperature. Results are validated until the onset of carbon formation is detected through differential pressure measurement. The primary purpose of this analysis is to identify the ideal conditions that will minimize coking in the system. Furthermore, the investigation emphasizes the impact of pressure that could potentially alter the onset time of coking formation and the blockage percentage in a mesh. This paper presents the results of coking experiments over a realistic range of pressure and temperature condition (pressures from 13.8 to 27.6 bar at 200°C).

Presenting Author: Anette Lira Texas A&M University

Presenting Author Biography: Anette Lira is a graduate research student from Texas A&M University. She graduated with a bachelor's in 2023 in mechanical engineering from the University of Prairie View A&M. She is currently working under Dr. Eric Petersen at the Turbomachinery Laboratory where she focuses under coking processes for fuels.

Authors:

Anette Lira Texas A&M University
Raquel Juarez Texas A&M University
Codruta Loebick Precision Combustion Inc
Eric L. Petersen Texas A&M University