scholarly journals Dynamic Mechanics of Rigid Helicopter Systems During Ditching

2021 ◽  
Vol 10 (2) ◽  
pp. 439-447
Author(s):  
Mohamad Abu Ubaidah Amir Abu Zarim ◽  
Marja Azlima Omar
Keyword(s):  
Fluid Dynamics ◽  
Rigid Body ◽  
Federal Aviation Administration ◽  
Aviation Safety ◽  
Distinctive Features ◽  
Safe Water ◽  
Dynamic Relations ◽  
Multiphase Fluid ◽  
Kinetics Of

Aircraft and helicopter often fly above open waters and thus have to observe regulations to ensure safe water landing under emergency conditions. This practice is also referred to as ditching - one of several types of slamming problems that are under review by the current regulations of the Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA). Ditching is related to the controlled landing on water, with distinctive features such as hydrodynamic slamming loads, complex hydromechanics at tremendous forward speeds, as well as the interaction of multiphase fluid dynamics (air, water, and vapor). This paper presents the knowledge on system mechanics during helicopter ditching. The discussion begins with the fundamental kinetics of the rigid body, and then delves into dynamic relations to describe the effect of forces on motions. In the end, the paper discusses several relevant theories to further contribute to the understanding of the problem of impact.

Kinetics of a Rigid Body

2001 ◽  
pp. 135-163
Author(s):  
Oliver M. O’Reilly
Keyword(s):  
Rigid Body ◽  
Kinetics Of

Kinetics of a Rigid Body

2019 ◽  
pp. 205-242
Author(s):  
Oliver M. O’Reilly
Keyword(s):  
Rigid Body ◽  
Kinetics Of

Review and Implementation Analysis of Safety Management Systems in Aviation Design

2015 ◽  
Vol 2 (1) ◽  
pp. 21-32
Author(s):  
Heidi C. Kim
Keyword(s):  
Safety Management ◽  
Federal Aviation Administration ◽  
Aviation Safety ◽  
Management Systems ◽  
Federal Regulations ◽  
Safety Management Systems ◽  
Regulatory Requirements ◽  
Management Processes ◽  
Part 121 ◽  
Air Carriers

In January of 2015, the Federal Aviation Administration (FAA) released an 80-page document outlining Safety Management Systems (SMS) for Title 14 of the Code of Federal Regulations (14 CFR) part 121 air carriers. This advisory circular provides a description of regulatory requirements, methods of development, and implementation of an SMS (Federal Aviation Administration, 2015). The release of this document began a race to implement SMS across aviation. An all-encompassing Safety Management System currently does not apply to the manufacturing of airplane parts. This research will examine current safety management processes in place for applicants and holders of supplemental type certificates (STC). Upon review of current procedures, a model for an SMS will be created specific to supplemental type certificate applicants and holders. This SMS process created for STC holders will ultimately improve aviation safety. The FAA should mandate this framework for all applicants pursuing and holding a supplemental type certificate.

Cooling and Freezing of Cashew Apple Using Computational Fluid Dynamics

2020 ◽  
Vol 25 ◽  
pp. 114-132 ◽  
Author(s):  
V.A. Agra Brandão ◽  
R. Araújo de Queiroz ◽  
R. Lima Dantas ◽  
G. Santos de Lima ◽  
N. Lima Tresena ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nutritional Value ◽  
Fruits And Vegetables ◽  
Numerical Study ◽  
Freezing Process ◽  
Ansys Cfx ◽  
Cashew Apple ◽  
Freezing Period ◽  
Kinetics Of

Freezing is one the most efficient methods for conservation, especially, fruits and vegetables. Cashew is a fruit with high nutritional value and great economic importance in the Northeast region of Brazil, however, due to high moisture content, it is highly perishable. The numerical study of the freezing process is of great importance for the optimization of the process. In this sense, the objective of this work was to study the cooling and freezing processes of cashew apple using computational fluid dynamics technique. Experiments of cooling and freezing of the fruit, with the aid of a refrigerator,data acquisition system and thermocouples, and simulation using Ansys CFX® software for obtain the cooling and freezing kinetics of the product were realized. Results of the cooling and freezing kinetics of the cashew apple and temperature distribution inside the cashew apple are presented, compared and analyzed. The model was able to predict temperaturetransient behavior with good accuracy, except in the post-freezing period.

scholarly journals Modulating yaw with an unstable rigid body and a course-stabilizing or steering caudal fin in the yellow boxfish ( Ostracion cubicus )

2020 ◽  
Vol 7 (4) ◽  
pp. 200129 ◽  
Author(s):  
Pim G. Boute ◽  
Sam Van Wassenbergh ◽  
Eize J. Stamhuis
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Rigid Body ◽  
Body Shape ◽  
Cross Sectional ◽  
Caudal Fin ◽  
Stabilizing Effect ◽  
Flow Speeds ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

Despite that boxfishes have a rigid carapace that restricts body undulation, they are highly manoeuvrable and manage to swim with remarkably dynamic stability. Recent research has indicated that the rigid body shape of boxfishes shows an inherently unstable response in its rotations caused by course-disturbing flows. Hence, any net stabilizing effect should come from the fishes' fins. The aim of the current study was to determine the effect of the surface area and orientation of the caudal fin on the yaw torque exerted on the yellow boxfish, Ostracion cubicus , a square cross-sectional shaped species of boxfish. Yaw torques quantified in a flow tank using a physical model with an attachable closed or open caudal fin at different body and tail angles and at different water flow speeds showed that the caudal fin is crucial for controlling yaw. These flow tank results were confirmed by computational fluid dynamics simulations. The caudal fin acts as both a course-stabilizer and rudder for the naturally unstable rigid body with regard to yaw. Boxfishes seem to use the interaction of the unstable body and active changes in the shape and orientation of the caudal fin to modulate manoeuvrability and stability.

Inviscid Store Separation During Transonic Flight With Deployable Fins Using (6+) DOF

2004 ◽  
Author(s):  
Jonathan G. Dudley ◽  
William Westmoreland
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Rigid Body ◽  
Reference Frames ◽  
Dynamics Model ◽  
Cfd Simulations ◽  
Fighter Aircraft ◽  
Computational Fluid Dynamics Model ◽  
Store Separation

The classical rigid body 6 DOF capability at Eglin AFB has been completely rewritten. The new (6+) DOF allows moving components relative to non-inertial reference frames during time accurate CFD simulations. An inviscid computational fluid dynamics model was prepared to investigate the separation of a 2,000 lb cluster munition (CBU104) with deployable fins from an F15-E at transonic speed using (6+) DOF. The Mach effects of the store with deployable fins were studied for a given fighter aircraft configuration prior to USAF flight clearance.

scholarly journals Spectroscopic and Microscopic Approaches for Investigating the Dynamic Interactions of Anti-microbial Peptides With Membranes and Cells

2021 ◽  
Vol 2 ◽  
Author(s):  
Andrew H. A. Clayton
Keyword(s):  
Fluid Dynamics ◽  
Health System ◽  
Mechanism Of Action ◽  
Dynamic Interactions ◽  
Defense Systems ◽  
Complex Landscape ◽  
Human Use ◽  
Conventional Antibiotics ◽  
Kinetics Of ◽  
Membrane Molecule

The emergence of microbes resistant to conventional antibiotics is a burgeoning threat to humanity with significant impacts on the health of people and on the health system itself. Antimicrobial peptides (AMPs) hold promise as potential future alternatives to conventional drugs because they form an integral part of the defense systems of other species in the animal, plant, and fungal kingdoms. To aid the design of the next generation of AMPs optimized for human use, we must first understand the mechanism of action of existing AMPs with their targets, ideally in the context of the complex landscape of the living (microbial) cell. Advances in lasers, optics, detectors, fluid dynamics and various probes has enabled the experimentalist to measure the kinetics of molecule–membrane, molecule–molecule, and molecule–cell interactions with increasing spatial and temporal resolution. The purpose of this review is to highlight studies into these dynamic interactions with a view to improving our understanding of AMP mechanisms.

Geometric Insight Into the Dynamics of a Rigid Body Using the Spatial Triangle of Screws

2001 ◽  
Author(s):  
Gordon R. Pennock ◽  
Patrick J. Meehan
Keyword(s):  
Rigid Body ◽  
Closed Loop ◽  
Equations Of Motion ◽  
Analytical Techniques ◽  
Rate Of Change ◽  
Time Rate ◽  
Open Chain ◽  
Spatial Mechanisms ◽  
Kinetics Of ◽  
Insight Into

Abstract Geometric relationships between the velocity screw and momentum screw are presented, and the dual angle between these two screws is shown to provide important insight into the kinetics of a rigid body. Then the centripetal screw is defined, and the significance of this screw in a study of the dynamics of a rigid body is explained. The dual-Euler equation, which is the dual form of the Newton-Euler equations of motion, is shown to be a spatial triangle. The vertices of the triangle are the centripetal screw, the time rate of change of momentum screw, and the force screw. The sides of the triangle are three dual angles between the three vertices. The spatial triangle provides valuable geometrical insight into the dynamics of a rigid body and is believed to be a meaningful alternative to existing analytical techniques. The authors believe that the work presented in this paper will prove useful in a dynamic analysis of closed-loop spatial mechanisms and multi-rigid body open-chain systems.

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