Airport Pavement Groove Identification and Analysis at NAPTF

2013 ◽  
Vol 723 ◽  
pp. 1003-1010 ◽  
Author(s):  
Qiang Wang ◽  
Josh Davis
Keyword(s):  
High Speed ◽  
Federal Aviation Administration ◽  
Automatic Device ◽  
Test Facility ◽  
Laser Sensor ◽  
Rigid Pavement ◽  
Airport Pavement ◽  
Grooved Surface ◽  
Groove Configurations ◽  
Transverse Grooves

Transverse grooves in an airport pavement allow water to be ejected from beneath the tires of an aircraft moving at high speed. It has been found that the grooves can efficiently reduce the hydroplaning potential of a pavement during wet weather. The Federal Aviation Administration (FAA) maintains a standard specification for groove configuration immediately after construction and during service. The National Airport Pavement Test Facility (NAPTF) performed a long period of real scale tests to investigate the performance of the current FAA standard square grooves and proposed trapezoidal grooves. This paper includes the comparison of trapezoidal and rectangular grooves under aircraft tire loading with service life. These two groove patterns were constructed on the flexible and rigid pavement respectively. In the automatic device measurement, a laser sensor from a truss profiler constantly detected the distance between the grooved surface and an initial standard line as the aircraft tires repeatedly passed through the grooved areas. An automatic groove identification program was also developed to evaluate the groove configurations. Our test results demonstrate that the trapezoidal grooves maintain a longer life shape configuration than rectangular grooves, especially for asphalt pavements.

Subgrade stress ratios as airfield pavement rutting performance indicators

2007 ◽  
Vol 34 (2) ◽  
pp. 189-198
Author(s):  
Kasthurirangan Gopalakrishnan ◽  
Marshall R Thompson
Keyword(s):  
Transfer Functions ◽  
Flexible Pavements ◽  
Federal Aviation Administration ◽  
Flexible Pavement ◽  
Test Facility ◽  
Airport Pavement ◽  
Study Results ◽  
The Us ◽  
Stress Ratios ◽  
New Generation

Rutting is a major distress in airport flexible pavements. Subgrade vertical strain criteria are used in many airport flexible pavement design procedures to consider the development of rutting. Several research studies have identified the limitations associated with these criteria. Design criteria based on subgrade stress ratios (SSRs) are being considered for evaluating subgrade rutting in airport flexible pavements. In this paper, the SSRs based on measured vertical subgrade stresses are related to surface rutting in flexible pavements subjected to repeated trafficking of Boeing 777 and 747 simulated test gears at the US Federal Aviation Administration (FAA) National Airport Pavement Test Facility (NAPTF). The results indicated overstressing of the subgrade in two test sections, and this was confirmed by trench study results. A good correlation was obtained between the SSRs and the surface rut depths, supporting the validity of developing SSR-based rutting transfer functions for airport flexible pavements serving the next generation of aircraft.Key words: rutting, subgrade stress ratio (SSR), National Airport Pavement Test Facility (NAPTF), pressure cell (PC), new generation aircraft, airport flexible pavement.

Iterative Framework for Performance and Environmental Impacts of Airfields

2019 ◽  
Vol 2673 (9) ◽  
pp. 179-187
Author(s):  
Izak M. Said ◽  
Imad L. Al-Qadi
Keyword(s):  
Life Cycle ◽  
Energy Demand ◽  
Federal Aviation Administration ◽  
Test Facility ◽  
Traffic Loading ◽  
Secondary Sources ◽  
Field Instrumentation ◽  
Airport Pavement ◽  
Performance Check ◽  
Layered Design

The main goal of a durable and sustainable airfield is to withstand repeated aircraft traffic loading while minimizing the environmental impact. The objective of this study is to develop a design-life cycle assessment (LCA) framework considering a balanced evaluation of structural adequacy, minimizing emission, and optimizing total energy demand. To achieve this objective, three steps are introduced: an evaluation of the structural adequacy of the design using the Federal Aviation Administration (FAA) pavement design software FAA rigid and flexible iterative elastic layered design; a preliminary performance check using field instrumentation responses; and a LCA of airfield sections using both deterministic and probabilistic approaches. In addition to presenting the design-LCA methodology, this paper offers a comparative evaluation that covers two perpetual designs (LFP1-N and LFP4-N) and one conventional section (LFC5-N). These pavement sections were built and tested at the National Airport Pavement Test Facility as part of construction cycle 7, funded by the FAA. Responses collected from instrumentation were used to compute field-based coverages to failure. Moreover, life cycle inventories from secondary sources were used to quantify the greenhouse gas emissions and energy demand associated with the construction of these sections. Results show inconsistencies between the field-predicted and theoretically predicted performance. This suggests the need for the additional calibration of the currently used performance models. Moreover, this study shows that under a specific asphalt concrete (AC) thickness limit, conventional AC may be more eco-friendly than a perpetual design.

Airfield Pavement Damage Evaluation Due to New-Generation Aircraft Wheel Loading and Wander Patterns

2018 ◽  
Vol 2672 (29) ◽  
pp. 82-92 ◽  
Author(s):  
Priyanka Sarker ◽  
Erol Tutumluer
Keyword(s):  
Residual Deformation ◽  
Federal Aviation Administration ◽  
Test Facility ◽  
Initial Attempt ◽  
Stress History ◽  
History Effects ◽  
Aircraft Landing ◽  
Airport Pavement ◽  
Wheel Loading ◽  
Pavement Damage

This paper presents a stress-history-based approach to predict the deformation basins of airport pavements subjected to heavy aircraft loading applied in sequential wanders. Multi-depth deflectometer data from full-scale aircraft landing gear tests conducted at the National Airport Pavement Test Facility built by the Federal Aviation Administration are used to create individual pass residual deformation transverse profiles. The computed residual deformation profiles are further corrected for stress-history effects to predict rut in the selected test sections. The developed model focuses on using the previous load location and stress history of the soil element to develop the deformations in that element. Despite the unavailability of the surface transverse profile data measured in the field at different passes, the initial attempt of the model can closely predict the deformation profile similar to width and shape expected in the field. And after the stress-history effects are accounted for, the initially calculated rut depth decreases significantly to match the final contour basin of the test sections extracted from the post traffic trenching. The advantage of using the stress-history-effects-based rut prediction tool is that it can allow any combination of wander positions and sequences of load applications to be accounted for their effects on the final surface rut development.

Parameter Sensitivity Analysis of Airport Rigid Pavement Thickness Using FAARFIELD Program

2011 ◽  
Vol 243-249 ◽  
pp. 4068-4074 ◽  
Author(s):  
Tammam Merhej ◽  
De Cheng Feng
Keyword(s):  
Sensitivity Analysis ◽  
Input Parameter ◽  
Federal Aviation Administration ◽  
The United States ◽  
Modulus Of Rupture ◽  
Rigid Pavement ◽  
Airport Pavement ◽  
Input Parameters ◽  
Layered Design ◽  
Pavement Thickness

Federal aviation administration rigid and flexible iterative elastic layered design (FAARFIELD) software program became the exclusive approved method for airport pavement thickness design adopted by federal aviation administration (FAA) in the United States after the advisory circular AC150/5320-6E “Airport Pavement Design and Evaluation” was issued in September 2009. In this paper, a sensitivity analysis was conducted to investigate the effect of FAARFIELD input parameters on the required thickness of the airport rigid pavement. The input parameters studied are: concrete flexural strength (modulus of rupture, MOR), the subgrade reaction modulus, K, subbase layers and air traffic mix .Each evaluated input parameter was varied within its recommended range to study its effect on the required thickness of the airport pavement. It was found that the concrete modulus of rupture is the most sensitive parameter on the required thickness.

Experimental Inverstigations On the Pressure Fluctuations in the Sealing Gap of Dry Gas Seals with Embedded Pressure Sensors

2021 ◽  
Author(s):  
Jingjing Luo ◽  
Dieter Brillert
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Static Pressure ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Test Facility ◽  
Experimental Investigations ◽  
Mechanical Seals ◽  
Process Gas ◽  
Sealing Gap

Abstract Dry gas lubricated non-contacting mechanical seals (DGS), most commonly found in centrifugal compressors, prevent the process gas flow into the atmosphere. Especially when high speed is combined with high pressure, DGS is the preferred choice over other sealing alternatives. In order to investigate the flow field in the sealing gap and to facilitate the numerical prediction of the seal performance, a dedicated test facility is developed to carry out the measurement of key parameters in the gas film. Gas in the sealing film varies according to the seal inlet pressure, and the thickness of gas film depends on this fluctuated pressure. In this paper, the test facility, measurement methods and the first results of static pressure measurements in the sealing gap of the DGS obtained in the described test facility are presented. An industry DGS with three-dimensional grooves on the surface of the rotating ring, where experimental investigations take place, is used. The static pressure in the gas film is measured, up to 20 bar and 8,100 rpm, by several high frequency ultraminiature pressure transducers embedded into the stationary ring. The experimental results are discussed and compared with the numerical model programmed in MATLAB, the characteristic and magnitude of which have a good agreement with the numerical simulations. It suggests the feasibility of measuring pressure profiles of the standard industry DGS under pressurized dynamic operating conditions without altering the key components of the seal and thereby affecting the seal performance.

scholarly journals Tip Clearance Actuation With Magnetic Bearings for High-Speed Compressor Stall Control

2000 ◽  
Vol 123 (3) ◽  
pp. 464-472 ◽  
Author(s):  
Z. S. Spakovszky ◽  
J. D. Paduano ◽  
R. Larsonneur ◽  
A. Traxler ◽  
M. M. Bright
Keyword(s):  
High Speed ◽  
Design Procedure ◽  
Magnetic Bearing ◽  
Rotating Stall ◽  
Tip Clearance ◽  
Magnetic Bearings ◽  
Test Facility ◽  
Control Analysis ◽  
Servo Actuator ◽  
Stall Control

Magnetic bearings are widely used as active suspension devices in rotating machinery, mainly for active vibration control purposes. The concept of active tip-clearance control suggests a new application of magnetic bearings as servo-actuators to stabilize rotating stall in axial compressors. This paper presents a first-of-a-kind feasibility study of an active stall control experiment with a magnetic bearing servo-actuator in the NASA Glenn high-speed single-stage compressor test facility. Together with CFD and experimental data a two-dimensional, incompressible compressor stability model was used in a stochastic estimation and control analysis to determine the required magnetic bearing performance for compressor stall control. The resulting requirements introduced new challenges to the magnetic bearing actuator design. A magnetic bearing servo-actuator was designed that fulfilled the performance specifications. Control laws were then developed to stabilize the compressor shaft. In a second control loop, a constant gain controller was implemented to stabilize rotating stall. A detailed closed loop simulation at 100 percent corrected design speed resulted in a 2.3 percent reduction of stalling mass flow, which is comparable to results obtained in the same compressor by Weigl et al. (1998. ASME J. Turbomach. 120, 625–636) using unsteady air injection. The design and simulation results presented here establish the viability of magnetic bearings for stall control in aero-engine high-speed compressors. Furthermore, the paper outlines a general design procedure to develop magnetic bearing servo-actuators for high-speed turbomachinery.

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