APU-Noise Reduction by Novel Muffler Concepts

2018 ◽  
Author(s):  
Karsten Knobloch ◽  
Lars Enghardt ◽  
Friedrich Bake
Keyword(s):  
Noise Reduction ◽  
Operating Conditions ◽  
Acoustic Damping ◽  
Broadband Absorption ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Absorber Material ◽  
Bias Flow ◽  
Downstream Section ◽  
Broadband Sound

For a GTCP36-28 auxiliary power unit (APU), a set of mufflers has been designed and tested for some representative operating conditions. The first muffler design uses cavities of different sizes in conjunction with a bias flow for efficient broadband sound absorption. The second design — also expected to perform well over a large frequency range — makes use of a variable perforation and some porous absorber material. The acoustic damping performance of the mufflers was assessed using a downstream section of dedicated microphone probes. Individual spectra and circumferential averages have been computed and are used for a comparison to a hard-walled duct section of the same length. Results show a reasonable broadband absorption for most configurations. For one operating point, significant differences were found while comparing the performance of the cavity muffler with and without bias flow. The results suggest, that a small amount of air — less than initially expected — is sufficient to obtain the desired noise reduction.

ESTIMATION OF OPERATING CONDITIONS OF A MID-RANGE AIRCRAFT AUXILIARY POWER UNIT WITH RECEIVER INLET IN TURBULENT FLOW

2015 ◽  
Vol 46 (4) ◽  
pp. 365-393 ◽  
Author(s):  
Evgenii Petrovich Bykov ◽  
Egor Vyacheslavovich Kazhan ◽  
Vladimir Fedorovich Tretyakov
Keyword(s):  
Turbulent Flow ◽  
Power Unit ◽  
Operating Conditions ◽  
Auxiliary Power Unit ◽  
Auxiliary Power

Centrifugal Rotor Tri-Hub Burst For Containment System Validation

2006 ◽  
Author(s):  
B. Manavi
Keyword(s):  
Operating Conditions ◽  
Gas Generator ◽  
Element Analysis ◽  
Turbine Engine ◽  
Auxiliary Power Unit ◽  
Average Temperature ◽  
System Validation ◽  
Auxiliary Power ◽  
Predicted Values ◽  
2D And 3D

The following paper outlines a methodology for accurately predicting the burst of a centrifugal rotor, for the purpose of certifying the tri-hub containment capability of an Auxiliary Power Unit gas turbine engine. The tri hub burst is achieved by introducing three equally spaced slots into a centrifugal rotor. Using 2D and 3D finite element analysis, the slot geometry was optimized to ensure burst of the centrifugal rotor at the desired speed, through spin pit testing, and to account for thermal and centrifugal growth for operation in an engine with proper tip clearances. In order to validate the versatility of this methodology, two centrifugal rotor geometries with different material properties (Ti6Al4V and Ti6Al2Sn4Zr6Mo) and operating conditions were analyzed. The analytical predictions were confirmed with isothermal spit pit tests using temperatures that approximate the bulk average temperature in the high stressed bore for an un-slotted centrifugal rotor. The results of spin pit tests were found to be within 0.4% of predicted values. Burst tests were subsequently conducted on a gas generator rig and a full engine test, where results were found to be within 2% of predicted values.

КОНЦЕПЦІЯ СТВОРЕННЯ СИЛОВОЇ УСТАНОВКИ СІМЕЙСТВА РЕГІОНАЛЬНИХ ПАСАЖИРСЬКИХ ЛІТАКІВ АН-148/АН-158

2019 ◽  
pp. 50-63
Author(s):  
О. Д. Донець ◽  
В. П. Іщук
Keyword(s):  
Power Plant ◽  
Noise Reduction ◽  
Fuel Consumption ◽  
Electronic System ◽  
Electronic Control ◽  
Level Of Automation ◽  
Auxiliary Power ◽  
Power Plant Control ◽  
Technical Status ◽  
Air Intake

The basic results of calculation and research works carried out in the process of creation of power unit of regional passenger airplanes’ family are given. The design features of the propulsion engines and engine of the auxiliary power plant are described. The aforementioned propulsion system includes propulsion engines D-436-148 and engine AI-450-MS of auxiliary power plant. In order to comply with the requirements of Section 4 of the ICAO standard (noise reduction of the aircraft in site), in part of ensuring the noise reduction of engines, when creating the power plant of the An-148/An-158 aircraft family, a single- and double-layer acoustic filler was used in the structure of the engine nacelle and air intake. The use of electronic system for automatic control of propulsion engines such as FADEC and its integration into the digital airborne aircraft complex ensured the operation of engines, included in the power plant provided with high specific fuel consumption, as well as increased the level of automation of the power plant control and monitoring, and ensured aircraft automation landing in ICAO category 3A. In addition, the use of the aforementioned electronic system, allowed to operate the power plant of the aircraft in accordance with technical status. The use of the AI-450-MS auxiliary power plant with an electronic control system such as FADEC, and the drive of the service compressor from a free turbine, eliminated the effect of changes in power and air takeoff, on the deviation of the engine from optimal mode, which also minimized the fuel consumption. The use of fuel metering system TIS-158, allowed to ensure control of its condition and assemblies, without the use of auxiliary devices, built-in control means. In the fire protection system, the use of the electronic control and monitor unit, as well as the use of digital serial code for the exchange of information between the elements of the system and the aircraft systems, has reduced the number of connections, which increased the reliability of the system and reduced its weight characteristics.

Approximation of Payback Period of Fuel Cell Auxiliary Power Unit for Large Trucks

2009 ◽  
Vol 129 (2) ◽  
pp. 228-229
Author(s):  
Noboru Katayama ◽  
Hideyuki Kamiyama ◽  
Yusuke Kudo ◽  
Sumio Kogoshi ◽  
Takafumi Fukada
Keyword(s):  
Fuel Cell ◽  
Power Unit ◽  
Payback Period ◽  
Auxiliary Power Unit ◽  
Auxiliary Power

scholarly journals Improving EGT sensing data anomaly detection of aircraft auxiliary power unit

2020 ◽  
Vol 33 (2) ◽  
pp. 448-455 ◽  
Author(s):  
Liansheng LIU ◽  
Yu PENG ◽  
Lulu WANG ◽  
Yu DONG ◽  
Datong LIU ◽  
...  
Keyword(s):  
Anomaly Detection ◽  
Power Unit ◽  
Sensing Data ◽  
Auxiliary Power Unit ◽  
Auxiliary Power

Low-Emissions Technology Development for Auxiliary Power Unit Combustion Systems

2021 ◽  
Author(s):  
Thomas Bronson ◽  
Rudy Dudebout ◽  
Nagaraja Rudrapatna
Keyword(s):  
Gas Turbine ◽  
Power Unit ◽  
Fuel Injection ◽  
Oxides Of Nitrogen ◽  
Combustion System ◽  
Auxiliary Power Unit ◽  
Criteria Pollutants ◽  
Auxiliary Power ◽  
Combustion Systems ◽  
Aircraft Application

Abstract The aircraft Auxiliary Power Unit (APU) is required to provide power to start the main engines, conditioned air and power when there are no facilities available and, most importantly, emergency power during flight operation. Given the primary purpose of providing backup power, APUs have historically been designed to be extremely reliable while minimizing weight and fabrication cost. Since APUs are operated at airports especially during taxi operations, the emissions from the APUs contribute to local air quality. There is clearly significant regulatory and public interest in reducing emissions from all sources at airports, including from APUs. As such, there is a need to develop technologies that reduce criteria pollutants, namely oxides of nitrogen (NOx), unburned hydrocarbons (UHC), carbon monoxide (CO) and smoke (SN) from aircraft APUs. Honeywell has developed a Low-Emissions (Low-E) combustion system technology for the 131-9 and HGT750 family of APUs to provide significant reduction in pollutants for narrow-body aircraft application. This article focuses on the combustor technology and processes that have been successfully utilized in this endeavor, with an emphasis on abating NOx. This paper describes the 131-9/HGT750 APU, the requirements and challenges for small gas turbine engines, and the selected strategy of Rich-Quench-Lean (RQL) combustion. Analytical and experimental results are presented for the current generation of APU combustion systems as well as the Low-E system. The implementation of RQL aerodynamics is well understood within the aero-gas turbine engine industry, but the application of RQL technology in a configuration with tangential liquid fuel injection which is also required to meet altitude ignition at 41,000 ft is the novelty of this development. The Low-E combustion system has demonstrated more than 25% reduction in NOx (dependent on the cycle of operation) vs. the conventional 131-9 combustion system while meeting significant margins in other criteria pollutants. In addition, the Low-E combustion system achieved these successes as a “drop-in” configuration within the existing envelope, and without significantly impacting combustor/turbine durability, combustor pressure drop, or lean stability.

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