Aviation

Effect of an Excrescence in the Slat Cove: Flow-field, Acoustic Radiation and Coherent Structures

Souza, DS
Rodriguez, DA
Simões, LGC
Medeiros, MAF
2015

Slat noise during aircraft landing is already a barrier to the development of quieter commercial airplanes. Investigations have been made by several research groups to understand the mechanism of slat noise generation. Most of the published works related to slat noise consider clean idealized geometries, whereas real slats contain some imperfections to enable its operation. The influence of a protrusion on the slat...

Wavepacket Models for Subsonic Twin Jets Using 3D Parabolized Stability Equations

Rodriguez, DA
Jotkar, MR
Gennaro, EM
2018

An extension of the classical parabolized stability equations to flows strongly dependent on the two cross-stream spatial directions and weakly dependent on the streamwise one is applied to model the large-scale structures present in twin-jet configurations. The existence of these ...

The Effect of Compressibility on the Primary Global Instability of Unforced Laminar Separation Bubbles

Gennaro, EM
Souza, BDP
Rodriguez, D
2019

Laminar separation bubbles present a three-dimensional self-excited instability mechanism which leads to the appearance of spanwise-periodic structures. In incompressible flow, this mechanism was found to become active at conditions in which wave-like, two-dimensional perturbations are only convectively unstable. In the absence of continuous external excitation, the three-dimensional instability is expected to dominate the flow dynamics and initiate the laminar-turbulent transition. This work extends previous analyses by incorporating the effect of compressibility at subsonic...

A Combined Quantitative and Qualitative Approach to Planning for Improved Intermodal Connectivity at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Ceder, Avi
Tung, Steven
Tso, Kristin
Shladover, Steven
Xiong, Jing
Yoon, Sangwon
2009

This report has been prepared as the final deliverable for a research project developing a combined quantitative and qualitative approach to planning for improved intermodal connectivity at California airports. The quantitative approach involves the development of an Intermodal Airport Ground Access Planning Tool (IAPT) that combines transportation system performance measurement, an air passenger mode choice model, and a model of transportation provider behavior, and is designed to interface with a traffic network analysis model. The qualitative approach is used to enhance the quantitative...

Opportunities for Improved Intermodal Connectvitiy at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Xiong, Jing
2006

This working paper has been prepared as part of research to develop a combined quantitative and qualitative approach to planning for improved intermodal connectivity at California airports. The quantitative approach involves the development of an Intermodal Airport Ground Access Planning Tool that combines an air passenger model choice model, a model of transportation provider behavior and a traffic network analysis model. The qualitative approach will be used to enhance the quantitative analysis to account for those factors which are difficult to quantify and to provide recommended policy...

Recirculating Coherent Structures Inside the Cove of a Bulb Sealed Slat

Himeno, FHT
Amaral, FR
Souza, DS
Rodriguez, D
Medeiros, MAF
2019

The current aircraft noise has a large contribution provenient from the airframe in which the most relevant sources are the landing gear, the flap and the slat. The leading edge slat is a distributed noise source since it spans almost the whole wing extension. The presence of excrescences inside the slat cove can change significantly the recirculating flow and the characteristics of noise generated. Previous experiments showed substantial increasing in the narrow band peaks for the MD30P30N high-lift model in which the slat geometry included a bulb seal attached at some positions of its...

Using Technology to Improve Transportation Services

Garrison, William L.
1988

Today's transportation systems are well deployed in the developed nations, and they and their supporting activities are technologically and institutionally mature. This situation is exceptional in the perspective of the last 200 years of transportation development, during which new systems were innovated and wave after wave of construction undertaken.An examination of the ways technologies were shaped and adopted in the past reveals that today's view of technology-based opportunities is also exceptional. Consistent with system maturity, the search for improvements is focused on marginal...

Truck Scheduling for Ground to Air Connectivity: Final Report

Hall, Randolph W.
Lo, Shih-Che
2002

A critical link in the overnight package business is the on-time arrival of trucks at airport terminals. Truck delays can delay the package sorting and transfer process, which can in turn delay aircraft departures from the local terminal, as well as aircraft departures from hub terminals that depend on timely aircraft arrivals. This report models the airport terminal as a queueing process with random bulk arrivals. The models have been implemented in a web-based decision support tool (Truck to Air Dispatch, TAD, available at the website ger309-pc16.usc.edu), which provides real-time...

The California Aviation System: Current Status and Recent Trends

Hansen, Mark M.
Gosling, Geoffrey D.
Kettunen, Tarja
Wilkins, Erik
2002

This report presents statistical information on passenger and cargo traffic, aircraft activity and delays at California airports. Five main topics are considered: passenger enplanements, air travel origin and destination (O-D) patterns, air cargo activity, aircraft operations, and airport delays. In most cases, we present data for the state as a whole, major regions within the state, and major airports within each region. Most of the data are compiled on an annual basis for the years from 1980 to 2000. The report concludes with a discussion of the changes in activity in the California...

Reversibility of the Time-Dependent Shortest Path Problem

Daganzo, Carlos F.
1998

Time-dependent shortest path problems arise in a variety of applications; e.g., dynamic traffic assignment (DTA), network control, automobile driver guidance, ship routing and airplane dispatching. In the majority of cases one seeks the cheapest (least generalized cost) or quickest route between an origin and a destination for a given time of departure. This is the "forward" shortest path problem. In some applications, however, e.g., when dispatching airplanes from airports and in DTA versions of the "morning commute problem", one seeks the cheapest or quickest routes for a given arrival...