scholarly journals Aircraft-engine particulate matter emissions from conventional and sustainable aviation fuel combustion: comparison of measurement techniques for mass, number, and size

2022 ◽  
Author(s):  
Joel C. Corbin ◽  
Tobias Schripp ◽  
Bruce E. Anderson ◽  
Greg J. Smallwood ◽  
Patrick LeClercq ◽  
...  

Abstract. Sustainable aviation fuels (SAFs) have different compositions compared to conventional petroleum jet fuels, particularly in terms of fuel sulphur and hydrocarbon content. These differences may change the amount and physicochemical properties of volatile and non-volatile particulate matter (nvPM) emitted by aircraft engines. In this study, we evaluate whether comparable nvPM measurement techniques respond similarly to nvPM produced by three blends of SAFs compared to three conventional fuels. Multiple SAF blends and conventional (Jet A-1) jet fuels were combusted in a V2527-A5 engine, while an additional conventional fuel (JP-8) was combusted in a CFM56-2C1 engine. We evaluated nvPM mass concentration measured by three real-time sampling techniques: photoacoustic spectroscopy, laser-induced incandescence, and the extinction-minus-scattering technique. Various commercial instruments were tested including three LII 300s, one PAX, one MSS+, and two CAPS PMSSA. Mass-based emission indices (EIm) reported by these techniques were similar, falling within 30 % of their geometric mean for EIm above 100 mg/kgfuel (approximately 10 μg PM m−3 at the instrument), this geometric mean was therefore used as a reference value. Additionally, two integrative measurement techniques were evaluated: filter photometry and particle size distribution (PSD) integration. The commercial instruments used were one TAP, one PSAP, and two SMPSs. These techniques are used in specific applications, such as on-board research aircraft to determine PM emissions at cruise. EIm reported by the alternative techniques fell within approximately 50 % of the mean aerosol-phase EIm. In addition, we measured PM-number-based emissions indices using PSDs and condensation particle counters. The commercial instruments used included TSI SMPSs, a Cambustion DMS500, and an AVL APC, and the data also fell within approximately 50 % of their geometric mean. The number-based emission indices were highly sensitive to the accuracy of the sampling-line penetration functions applied as corrections. In contrast, the EIm data were less sensitive to those corrections since a smaller volume fraction fell within the size range where corrections were substantial. A separate, dedicated experiment also showed that the operating laser fluence used in the LII 300 laser-induced incandescence instrument for aircraft engine nvPM measurement is adequate for a range of SAF blends investigated in this study. Overall, we conclude that all tested instruments are suitable for the measurement of nvPM emissions from the combustion of SAF blends in aircraft engines.

Author(s):  
Henrik von der Haar ◽  
Ulrich Hartmann ◽  
Christoph Hennecke ◽  
Friedrich Dinkelacker ◽  
Joerg R. Seume

Defects in combustion chambers of aircraft engines might have an impact on the reliability of the downstream turbine and the machine’s performance. Detecting failures in the combustion chamber of an aircraft engine during operation may improve the resource management and the availability of the system. Aim of the ongoing research project is to find an approach to evaluate the state of the jet engine by analyzing the temperature and emissions field in the exhaust jet. This investigation is part of the collaborative research center SFB 871. The SFB 871 deals with the improvement of the regeneration process of complex capital goods such as aircraft engines. Maintenance, repair, and overhaul processes would be more efficient if the internal status of the engine would be known while still on the wing before it is disassembled. The feasibility of this approach is investigated for a pilot scaled model combustor, which provides optical access and allows the selection of “defined errors” in the combustor. It consists of an atmospheric tubular combustor with an array of eight premixed swirl burners with a maximum output of 160 kW. The operating conditions of one of the eight burners concerning power and air-fuel ratio, can be controlled. A power distribution between the burners is typical fault in an aircraft combustor and will be investigated in this study. It is observed that it is possible to determine small deviations by measuring density profiles applying a tomographic background-oriented schlieren (BOS) technique behind the combustor. Additionally, particle image velocimetry is used to measure differences in the velocity field of the exhaust gases. This study shows that a minimum power deviation of one burner in an array of a total of eight burners is detectable in the exhaust plane with the above mentioned measurement techniques.


Author(s):  
Pierre M. Dakhel ◽  
Stephen P. Lukachko ◽  
Ian A. Waitz ◽  
Richard C. Miake-Lye ◽  
Robert C. Brown

Recent measurements have suggested that soot properties can evolve downstream of the combustor, changing the characteristics of aviation particulate matter (PM) emissions and possibly altering the subsequent atmospheric impacts. This paper addresses the potential for the post-combustion thermodynamic environment to influence aircraft non-volatile PM emissions. Microphysical processes and interactions with gas phase species have been modeled for temperatures and pressures representative of in-service engines. Time-scale arguments are used to evaluate the relative contributions that various phenomena may make to the evolution of soot, including coagulation growth, ion-soot attachment, and vapor condensation. Then a higher-fidelity microphysics kinetic is employed to estimate the extent to which soot properties evolve as a result of these processes. Results suggest that limited opportunities exist for the modification of the size distribution of the soot, its charge distribution, or its volatile content, leading to the conclusion that the characteristics of the turbine and nozzle of an aircraft engine have little or no influence on aircraft non-volatile emissions. Combustor processing determines the properties of soot particulate matter emissions from aircraft engines, setting the stage for interactions with gaseous emissions and development as cloud condensation nuclei in the exhaust plume.


Author(s):  
David S. Liscinsky ◽  
Zhenhong Yu ◽  
Archer Jennings ◽  
Jay Peck ◽  
Bruce True ◽  
...  

Characterization of particulate matter (PM) emissions from commercial and military aircraft engines is a costly procedure, usually influenced by a number of uncontrollable technical issues such as ambient conditions. In this study we demonstrated that a research sector rig representing an aircraft engine combustor can be used to evaluate PM emissions, such as carbonaceous soot, in a well-controlled manner. PM emissions in terms of mass and number, as well as particle size distribution and optical properties, were characterized and quantified with a variety of state-of-the-art measurement instruments. Compared to previously published measurements on advanced commercial aircraft engines (CFM56-7B22), the measured emission index of black carbon soot was 58±3 mg/kg-fuel at simulated higher power conditions, consistent within 25% of field measurements. Measurements of number emission index were within a factor of 2 and geometric mean diameter was between 25 and 35nm again similar to field measurements on engines. Based on the measurements on particle mass and size, the mass mobility exponent of the soot particles had a lower limit of 2.4 indicating near-sphericity and an average density near 1 g/cm3.


Author(s):  
S. Ikezawa ◽  
T. Ueda

A contactless sensing system for nano-sized carbonaceous particulate matter using laser-induced incandescence (LII) and laser-induced breakdown spectroscopy (LIBS) is presented. The LIBS technique allows detecting elemental composition and density of the SPMs, and LII technique allows to measure particulate size. LII technique is temporal resolved method that enables measurement of soot particulate sizes in a combustion process. In the case of the measured material consisting of a carbonaceous element, it is easy to determine the particulate diameter distribution derived from the time-profile of emission attenuation signals during cooling process, because the cooling behaviour is characteristic of the particulate diameter in LII technique. However, in actuality, the SPMs consist of several different types of elements. By using LIBS technique, the elemental analysis is able to conduct easily.


2014 ◽  
pp. 898-907
Author(s):  
S. Ikezawa ◽  
T. Ueda

A contactless sensing system for nano-sized carbonaceous particulate matter using laser-induced incandescence (LII) and laser-induced breakdown spectroscopy (LIBS) is presented. The LIBS technique allows detecting elemental composition and density of the SPMs, and LII technique allows to measure particulate size. LII technique is temporal resolved method that enables measurement of soot particulate sizes in a combustion process. In the case of the measured material consisting of a carbonaceous element, it is easy to determine the particulate diameter distribution derived from the time-profile of emission attenuation signals during cooling process, because the cooling behaviour is characteristic of the particulate diameter in LII technique. However, in actuality, the SPMs consist of several different types of elements. By using LIBS technique, the elemental analysis is able to conduct easily.


2020 ◽  
Author(s):  
Joseph Matthews ◽  
Madhu Pandey

Propeller planes and small engine aircraft around the United States, legally utilize leaded aviation gasoline. The purpose of this experiment was to collect suspended particulate matter from a university campus, directly below an airport’s arriving flight path’s descent line, and to analyze lead content suspended in the air. Two collection sets of three separate samples were collected on six separate days, one set in July of 2018 and the second set in January 2019.


1986 ◽  
Vol 64 (11) ◽  
pp. 2624-2633 ◽  
Author(s):  
Peter F. Major ◽  
Lawrence M. Dill ◽  
David M. Eaves

Three-dimensional interactions between grouped aerial predators (frontal discs of aircraft engines), either linearly arrayed or clustered, and flocks of small birds were studied using interactive computer simulation techniques. Each predator modelled was orders of magnitude larger than an individual prey, but the prey flock was larger than each predator. Expected numbers of individual prey captured from flocks were determined for various predator speeds and trajectories, flock–predator initial distances and angles, and flock sizes, shapes, densities, trajectories, and speeds. Generally, larger predators and clustered predators caught more prey. The simulation techniques employed in this study may also prove useful in studies of predator–prey interactions between schools or swarms of small aquatic prey species and their much larger vertebrate predators, such as mysticete cetaceans.The study also provides a method to study problems associated with turbine aircraft engine damage caused by the ingestion of small flocking birds, as well as net sampling of organisms in open aquatic environments.


2017 ◽  
Author(s):  
Duseong S. Jo ◽  
Rokjin J. Park ◽  
Jaein I. Jeong ◽  
Gabriele Curci ◽  
Hyung-Min Lee ◽  
...  

Abstract. Single Scattering Albedo (SSA), the ratio of scattering efficiency to total extinction efficiency, is an essential parameter used to estimate the Direct Radiative Forcing (DRF) of aerosols. However, SSA is one of the large contributors to the uncertainty of DRF estimations. In this study, we examined the sensitivity of SSA calculations to the physical properties of absorbing aerosols, in particular, Black Carbon (BC), Brown Carbon (BrC), and dust. We used GEOS-Chem 3-D global chemical transport model (CTM) simulations and a post-processing tool for the aerosol optical properties (FlexAOD). The model and input parameters were evaluated by comparison against the observed aerosol mass concentrations and the Aerosol Optical Depth (AOD) values obtained from global surface observation networks such as the global Aerosol Mass Spectrometer (AMS) dataset, the Surface Particulate Matter Network (SPARTAN), and the Aerosol Robotic Network (AERONET). The model was generally successful in reproducing the observed variability of both the Particulate Matter 2.5 μm (PM2.5) and AOD (R ~ 0.76) values, although it underestimated the magnitudes by approximately 20 %. Our sensitivity tests of the SSA calculation revealed that the aerosol physical parameters, which have generally received less attention than the aerosol mass loadings, can cause large uncertainties in the resulting DRF estimation. For example, large variations in the calculated BC absorption may result from slight changes of the geometric mean radius, geometric standard deviation, real and imaginary refractive indices, and density. The inclusion of BrC and observationally-constrained dust size distributions also significantly affected the SSA, and resulted in a remarkable improvement for the simulated SSA at 440 nm (bias was reduced by 44–49 %) compared with the AERONET observations. Based on the simulations performed during this study, we found that the global aerosol direct radiative effect was increased by 10 % after the SSA bias was reduced.


Author(s):  
Kenro Obuchi ◽  
Fumiaki Watanabe ◽  
Hiroshi Kuroki ◽  
Hiroyuki Yagi ◽  
Kazuyoshi Arai

Ceramic matrix composites (CMCs) have lower density and a higher service temperature limit than nickel based alloys which have been used for turbine components of aircraft engines. These properties of CMCs have the potential to reduce the weight of turbine components and improve turbine thermal efficiency with a higher turbine inlet temperature (TIT). One of the technical issues of the CMC turbine vane is a relatively lower impact resistance than nickel based alloy turbine vanes. There are various previous works about impact resistance of CMCs, but there is little work that assumed actual engine conditions. The objective of this work was to verify the resistance of SiC/SiC CMC turbine vane to the impact phenomena that occur in the actual aircraft engine. The field damage survey was conducted on actual metal turbine vanes of commercial engines overhauled in IHI. The survey made it clear that the typical damage was less-than-0.127-mm-dent at the leading edge. In addition, the dropped weight impact test using the actual turbine airfoil which is made from a nickel based alloy was conducted at ambient temperature. The amount of energy required to make the dent of a certain size that was observed in actual metal turbine vanes was estimated. Then, the dropped weight impact test using the CMC test piece with a leading edge shape was conducted at the impact energy estimated by the metal turbine airfoil. The results showed that the failure mode of the CMC test piece was local damage with dents of a certain size and not a catastrophic failure mode. From this work, the damage to be assumed on CMC vane in actual aircraft engines was identified. As a future task, the effect of the damage to the fatigue capability of CMC turbine vanes needs to be investigated.


Author(s):  
Shubo Yang ◽  
Xi Wang

Limit protection, which frequently exists as an auxiliary part in control systems, is not the primary motive of control but is a necessary guarantee of safety. As in the case of aircraft engine control, the main objective is to provide the desired thrust based on the position of the throttle; nevertheless, limit protection is indispensable to keep the engine operating within limits. There are plenty of candidates that can be applied to design the regulators for limit protection. PID control with gain-scheduling technique has been used for decades in the aerospace industry. This classic approach suggests linearizing the original nonlinear model at different power-level points, developing PID controllers correspondingly, and then scheduling the linear time-invariant (LTI) controllers according to system states. Sliding mode control (SMC) is well-known with mature theories and numerous successful applications. With the one-sided convergence property, SMC is especially suitable for limit protection tasks. In the case of aircraft engine control, SMC regulators have been developed to supplant traditional linear regulators, where SMC can strictly keep relevant outputs within their limits and improve the control performance. In aircraft engine control field, we all know that the plant is a nonlinear system. However, the present design of the sliding controller is carried out with linear models, which severely restricts the valid scope of the controller. Even if the gain scheduling technique is adopted, the stability of the whole systems cannot be theoretically proved. Research of linear parameter varying (LPV) system throws light on a class of nonlinear control problems. In present works, we propose a controller design method based on the LPV model to solve the engines control problem and achieve considerable effectiveness. In this paper, we discuss the design of a sliding controller for limit protection task of aircraft engines, the plant of which is described as an LPV system instead of LTI models. We define the sliding surface as tracking errors and, with the aid of vertex property, present the stability analysis of the closed-loop system on the sliding surface. An SMC law is designed to guarantee that the closed-loop system is globally attracted to the sliding surface. Hot day (ISA+30° C) takeoff simulations based on a reliable turbofan model are presented, which test the proposed method for temperature protection and verify its stability and effectiveness.


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