Experimental Investigation of Cycle Properties, Noise, and Air Pollutant Emissions of an APS3200 Auxiliary Power Unit

Abstract

Auxiliary power unit (APU) operators face increasingly stricter airport requirements concerning exhaust gas and noise emission levels. To simultaneously reduce exhaust gas and noise emissions and to satisfy the increasing demand of electric power on board, optimization of the current technology is necessary. Prior to any possible demonstration of optimization potential, detailed data of thermodynamic properties and emissions have to be determined. Therefore, the investigations presented in this paper were conducted at a full-scale APU of an operational aircraft. A Pratt & Whitney APS3200, commonly installed in the Airbus A320 aircraft family, was used for measurements of the reference data. In order to describe the APS3200, the full spectrum of feasible power load and bleed air mass flow combinations were adjusted during the study. Their effect on different thermodynamic and performance properties, such as exhaust gas temperature, pressure as well as electric and overall efficiency is described. Furthermore, the mass flows of the inlet air, exhaust gas and fuel input were determined. Additionally, the work reports the exhaust gas emissions regarding the species CO 2 , CO and NOx as a function of load point. Moreover the acoustic noise emissions are presented and discussed. With the provided data the paper serves as a database for validating numerical simulations and provides a baseline for current APU technology.

Characterization of an Aircraft Auxiliary Power Unit Test Rig for Cycle Optimization Studies

“…This shows that 'no-bleed mode' is far off the design point of the GTCP36-28. This finding is in accordance with the results of the APS3200 APU [8] having a strictly linear trend as well. However, this pronounced offset at 'no-bleed mode' was not visible for the APS3200.…”

“…6 as a function of overall power output P ov . Based on the equations provided by Siebel et al [8] the overall power output is defined as P ov = P el + P bl (1) whereas the bleed air power P bl is determined by…”

“…7 both the electric efficiency η el and the overall efficiency η ov are shown as a function of P ov . Following Siebel et al [8] the electric efficiency is defined as…”

“…In the project's first step a widely used APU system was analyzed as a status quo. Here, the performance and noise emissions of the complete Hamilton Sundstrand APS3200 APU operating range, along with an analysis of the exhaust gas emissions has been previously studied by Siebel et al [8]. In a second step a test rig based on a GTCP36-28 APU system was set up as a demonstration platform and characterized in detail which is reported in the recent publication.…”

“…This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by/4.0/ The original publication is available at http://dx.doi.org/10.1115/1.4041119 turbine cycle as well as major exhaust gas emissions as a function of the APU load conditions. Furthermore, a comparison to the data of the APS3200 measured by Siebel et al [8] is given in order to evaluate the comparability of the demonstration cycle to a widely used aircraft APU system like the APS3200. Simulated data based on the validated cycle model of the GTCP36-28 is used to describe operating points and process parameters which were not accessible in the measurements.…”