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Aero-Acoustic Propulsion Laboratory

The Aero-Acoustic Propulsion Laboratory (AAPL) is a world-class facility for conducting aero-propulsion noise reduction research.

Facility Overview

Nozzle Acoustic Test Rig
Nozzle Acoustic Test Rig (NATR) in the Aero-Acoustic Propulsion Laboratory (AAPL).

With over 20 years of testing experience in acoustic research and development, the AAPL, located at NASA’s Glenn Research Center, is a world-class facility providing outstanding testing services in aircraft propulsion acoustic noise reduction and performance research.

Unique in testing capabilities and size, the AAPL dome is 65 ft high by 130 ft in diameter, providing an anechoic testing environment for engine component research and development. To provide a reflection free acoustic environment, 17,000 custom-designed 2‑ft thick fiberglass wedges are mounted on the dome’s interior walls and floor areas adjacent to the test rigs. The acoustically treated dome walls are designed specifically to attenuate sound. Together, these elements provide an acoustic testing environment that exceeds the acoustic research testing objectives set forth by NASA and industry.

AAPL houses three state-of-the-art acoustic test rigs, the Nozzle Acoustic Test Rig (NATR), Small Hot Jet Acoustic Rig (SHJAR), and the DGEN Aero-Propulsion Research Turbofan (DART).

Nozzle Acoustic Test Rig (NATR)

Nozzle Accoustic Test Rig Crew Exploration Vehicle
Nozzle Acoustic Test Rig (NATR) Crew Exploration Vehicle (CEV) 85-AA-Constellation, Orion Capsule and nozzle on the front of the NATR.

Designed specifically for acoustic and aerodynamic testing of advanced nozzle concepts, the NATR Free Jet, a 53-in. diameter, free-jet acoustic wind tunnel, is used to test a variety of aircraft technologies at simulated take-off and landing flight conditions up to Mach 0.35. The High-Flow Jet Exit Rig (HFJER) is used to mount test nozzle hardware within the NATR Free Jet. The HFJER is supplied with heated air to simulate the core and bypass flows of a turbofan engine. The NATR Free Jet and HFJER are uniquely suited to investigate engine nozzle acoustic performance, installation effects, and other aero-propulsion research as desired.

Located 50 ft from a test model, a fixed microphone array is used to acquire sideline and fly-by acoustic data. The data is processed and analyzed in real time during testing, improving data quality while reducing time and costs. The AAPL is one of the largest acoustic facilities in the world to feature a far-field measurement arena used for propulsion simulations.

Small Hot Jet Acoustic Rig

Particle Image Velocimetry
Particle image velocimetry (PIV) uses light reflected from seed particles in the flow to measure velocities of the air exhausting through nozzles in the Small Hot Jet Acoustic Test Rig (SHJAR).

The SHJAR provides researchers with an all-in-one platform to economically evaluate thrust performance, acoustic performance, and plume turbulence characteristics of new nozzle concepts.

The SHJAR can conduct laser-based plume turbulence studies with particle imaging velocimetry (PIV), shadowgraphy, Schlieren imaging, and a traversing plume-survey that can acquire high-resolution temperature and pressure profiles.

A 10-ft custom-built far-field measurement arena is used to obtain sideline or fly-by acoustic data. The data collected is processed and analyzed in real time during testing, optimizing test utilization and data quality while reducing time and costs.

DGEN Aero-Propulsion Research Turbofan

The DART provides a test bed for a variety of multi-discipline research. The DGEN 380 engine is a small turbofan that is representative of larger, more modern turbofan engines. The engine produces 570 lb of thrust and is approximately 48 in. long by 16 in. in diameter.

DART test bed can be used for:

Quick Facts

The Aero-Acoustic Propulsion Laboratory (AAPL) is a world-class facility providing outstanding testing services in aircraft noise reduction, with an emphasis in engine nozzle and fan components. Unique in testing capabilities and size, the AAPL dome is 65-ft high by 130-ft in diameter and covered with acoustic treatment internally to provide an anechoic testing environment for engine component research and development.

AAPL Test Rig Capabilities
Nozzle Acoustic Test Rig (NATR) Free Jet Wind Tunnel
Test section speed, Mach 0.0 to 0.35
Simulated altitude, ft Sea level
Test section total temperature, ˚R Ambient
NATR High-Flow Jet Exit Rig (HFJER)
Flow configurations Single (core) Dual  (core + bypass)
Maximum nozzle pressure ratio 4.5 4.5
Maximum core temperature, ˚F 1,425 1,280
Maximum fan/bypass temperature, ˚F 300
Maximum air flow rate (450 psig), lbm/s 30 30
Fuel Compressed natural gas  Compressed natural gas
*Optional independent third-stream airflow available.
Small Hot Jet Acoustic Rig (SHJAR)
Flow configurations Single (core)
Maximum nozzle pressure ratio 8
Maximum temperature, ˚F 1,300
Maximum air flow rate (450 psig) lbm/s 6
Fuel Gaseous hydrogen
DGEN Aero-Propulsion Research Turbofan (DART)
Fan diameter, in. 14
Bypass ratio 7.6 (two-spool unmixed flow)
Gear ratio 3.32
Thrust, lbf 570
Engine control Manual or automatic control via Full-Authority Digital Engine Control (FADEC)

Capabilities

The Aero-Acoustic Propulsion Lab houses three state-of-the-art test rigs for conducting aero-propulsion related research: NATR, SHJAR and DART.

Nozzle Acoustic Test Rig Free-Jet Wind Tunnel

Research Objectives

Description

Nozzle Acoustic Test Rig High-Flow Jet Exit Rig

Advanced Diagnostic Testing Capabilities

Model Data and Control System

Small Hot Jet Acoustic Rig

Research Objectives

Description

Capabilities

Advanced Diagnostic Testing Capabilities:

DGEN Aero-propulsion Research Turbofan

Research Objectives

Description

DGEN 380 Engine

DART TRUCK

WESTT BR Control Bench

Measurement Capabilities

Contact

Aero-Acoustic Propulsion Laboratory
Facility Manager: Jonathan Kubiak
216-433-8347
Jonathan.M.Kubiak@nasa.gov

Testing Division
21000 Brookpark Rd., MS 6-8
Cleveland, Ohio 44135
216-433-8301
William.P.Camperchioli@nasa.gov

If you are unsure about whom to contact about a specific facility question, please call our main number at 216-433-4000.

Using Our Facilities

NASA’s Glenn Research Center provides ground test facilities to industry, government, and academia. If you are considering testing in one of our facilities or would like further information about a specific facility or capability, please let us know.

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