A new queueing model for aircraft landing process

1997 ◽  
Author(s):  
Hong Chen ◽  
Yiyuan Zhao ◽  
Hong Chen ◽  
Yiyuan Zhao
Keyword(s):  
Queueing Model ◽  
Aircraft Landing

Calculation of Dynamic Tire Forces from Aircraft Instrumentation Data

2010 ◽  
Vol 38 (3) ◽  
pp. 182-193 ◽  
Author(s):  
Gary E. McKay
Keyword(s):  
System Performance ◽  
Equations Of Motion ◽  
Test Laboratory ◽  
Excellent Correlation ◽  
Friction Behavior ◽  
Aircraft Landing ◽  
Data Scatter ◽  
Tire Forces ◽  
Six Degree Of Freedom ◽  
Tire Friction

Abstract When evaluating aircraft brake control system performance, it is difficult to overstate the importance of understanding dynamic tire forces—especially those related to tire friction behavior. As important as they are, however, these dynamic tire forces cannot be easily or reliably measured. To fill this need, an analytical approach has been developed to determine instantaneous tire forces during aircraft landing, braking and taxi operations. The approach involves using aircraft instrumentation data to determine forces (other than tire forces), moments, and accelerations acting on the aircraft. Inserting these values into the aircraft’s six degree-of-freedom equations-of-motion allows solution for the tire forces. While there are significant challenges associated with this approach, results to date have exceeded expectations in terms of fidelity, consistency, and data scatter. The results show excellent correlation to tests conducted in a tire test laboratory. And, while the results generally follow accepted tire friction theories, there are noteworthy differences.

COMPARATIVE CHARACTERISTICS OF PHYSICAL AND MECHANICAL PROPERTIES OF COMPOSITE MATERIALS AND HIGH-STRENGTH STEEL 30FGSN2A

2020 ◽  
Author(s):  
I.R. Antypes ◽  
◽  
V.V. Zaitsev ◽  
Keyword(s):  
Composite Materials ◽  
High Strength Steel ◽  
Critical Stress ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Aviation Industry ◽  
Specific Strength ◽  
Aircraft Landing ◽  
Carbon Plastics ◽  
Aircraft Landing Gear

Currently, the use of composite materials is increasingly used in various areas of the national economy, including the aviation industry. The materials of this article are devoted to the study of the use of composite materials for the manufacture of aircraft landing gear in comparison with the traditionally used brand of steel. As a result of the work carried out, it was found that the slope made of carbon fiber showed a critical stress twice as high as its design made of 30xgsn2a steel. In addition, carbon plastics are superior to high-strength steel in terms of specific strength, stiffness, and tensile strength.

Interdependent Queueing Model with Varying Bulk Service

2012 ◽  
Vol 2 (1) ◽  
pp. 109 ◽  
Author(s):  
T. S. R Murthy ◽  
Sivarama Krishna ◽  
G. V. S Raju
Keyword(s):  
Queueing Model ◽  
Bulk Service

ALMAR 20

Alloy Digest ◽  
1964 ◽  
Vol 13 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Solid Fuel ◽  
Precipitation Hardening ◽  
Martensitic Steel ◽  
Heat Treating ◽  
Aircraft Landing ◽  
Temperature Performance ◽  
Aircraft Landing Gear ◽  
High Nickel

Abstract ALMAR 20 is a high nickel martensitic steel which is strengthened by precipitation hardening. It has excellent combination of strength and toughness particularly in the presence of notches and cracks. It is recommended for applications such as solid fuel rocket cases and aircraft landing gear. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-162. Producer or source: Allegheny Ludlum Corporation.

FERRIUM S53

Alloy Digest ◽  
2008 ◽  
Vol 57 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Heat Treating ◽  
Corrosion Resistant Steel ◽  
Resistant Steel ◽  
Corrosion Resistant ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Better Than

Abstract Ferrium S53 was developed for use as a structural corrosion resistant steel for aircraft landing gear. S53 has a corrosion resistance equivalent to 440C, strength equivalent to or better than 300M (AMS 6257A) and SAE 4340 (see Mechanical Properties), optimum microstructure features for maximum fatigue resistance, and a surface hardenability equal to or greater than 67 HRC for wear and fatigue. This datasheet is an update to Alloy Digest SS-942 and SS-1003. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating and machining. Filing Code: SA-589. Producer or source: QuesTek Innovations, LLC.

A Continuous-Class Queueing Model With Proportional Hazards-Based Routing

2018 ◽  
Author(s):  
Neal Master ◽  
Marty I. Reiman ◽  
Can Wang ◽  
Lawrence M. Wein
Keyword(s):  
Proportional Hazards ◽  
Queueing Model

scholarly journals A Taylor Series Approach for Service-Coupled Queueing Systems with Intermediate Load

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Ekaterina Evdokimova ◽  
Sabine Wittevrongel ◽  
Dieter Fiems
Keyword(s):  
Performance Measures ◽  
Queueing Systems ◽  
Poisson Processes ◽  
Series Expansions ◽  
Service Rate ◽  
Single Server ◽  
Queueing Model ◽  
State Space Explosion ◽  
Finite Queues ◽  
Service Rates

This paper investigates the performance of a queueing model with multiple finite queues and a single server. Departures from the queues are synchronised or coupled which means that a service completion leads to a departure in every queue and that service is temporarily interrupted whenever any of the queues is empty. We focus on the numerical analysis of this queueing model in a Markovian setting: the arrivals in the different queues constitute Poisson processes and the service times are exponentially distributed. Taking into account the state space explosion problem associated with multidimensional Markov processes, we calculate the terms in the series expansion in the service rate of the stationary distribution of the Markov chain as well as various performance measures when the system is (i) overloaded and (ii) under intermediate load. Our numerical results reveal that, by calculating the series expansions of performance measures around a few service rates, we get accurate estimates of various performance measures once the load is above 40% to 50%.

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