Influence of the Intermediate Flight Time on the Performance of Multistaged Sounding Rockets

Author(s):  
Glauco Partel ◽  
Rolf Engel
Keyword(s):  
2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 254
Author(s):  
Constance Woodman ◽  
Chris Biro ◽  
Donald J. Brightsmith

The release of captive-raised parrots to create or supplement wild populations has been critiqued due to variable survival rates and unreliable flocking behavior. Private bird owners free-fly their parrots in outdoor environments and utilize techniques that could address the needs of conservation breed and release projects. We present methods and results of a free-flight training technique used for 3 parrot flocks: A large-bodied (8 macaws of 3 species and 2 hybrids), small-bodied (25 individuals of 4 species), and a Sun Parakeet flock (4 individuals of 1 species). Obtained as chicks, the birds were hand-reared in an enriched environment. As juveniles, the birds were systematically exposed to increasingly complex wildland environments, mirroring the learning process of wild birds developing skills. The criteria we evaluated for each flock were predation rates, antipredator behavior, landscape navigation, and foraging. No parrots were lost to predation or disorientation during over 500 months of free-flight time, and all birds demonstrated effective flocking, desirable landscape navigation, and wild food usage. The authors conclude that this free-flight method may be directly applicable for conservation releases, similar to the use of falconry methods for raptor conservation.


2020 ◽  
Vol 53 (2) ◽  
pp. 9452-9457
Author(s):  
Yi Ji ◽  
Pei Pei ◽  
Defu Lin ◽  
Jianting Zhao ◽  
Wei Wang

2021 ◽  
Vol 11 (5) ◽  
pp. 2347 ◽  
Author(s):  
Jorge Solis ◽  
Christoffer Karlsson ◽  
Simon Johansson ◽  
Kristoffer Richardsson

This research aims to develop an automatic unmanned aerial vehicle (UAV)-based indoor environmental monitoring system for the acquisition of data at a very fine scale to detect rapid changes in environmental features of plants growing in greenhouses. Due to the complexity of the proposed research, in this paper we proposed an off-board distributed control system based on visual input for a micro aerial vehicle (MAV) able to hover, navigate, and fly to a desired target location without considerably affecting the effective flight time. Based on the experimental results, the MAV was able to land on the desired location within a radius of about 10 cm from the center point of the landing pad, with a reduction in the effective flight time of about 28%.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H Park

Abstract Background During flight, atmospheric pressure drop, low humidity and restricted motion occur. The environmental change can evoke the stroke occurrence. However, description of in-flight stroke case series has been limited until now. We investigated the clinical and flight trip characteristics of in-flight stroke cases in Korea. Method Since the opening of Incheon international airport, which is used by about 50 million people a year, in 2001, our hospital branch has been located at the airport and all the emergency stroke patients have been referred to our hospital. We performed retrospective review of the prospectively collected stroke registry and the information about the flight from January 2001 to December 2018. Results During the study period, 31 in-flight stroke cases were identified among total 1,452 ischemic stroke patients (17 men, 62±15 years old). Twenty-six patients had cerebral infarction, and four patients had transient ischemic attack. On etiological classification of cerebral infarction, 19 large artery atherothrombosis (61.3%), 1 septic embolism, 3 cryptogenic stroke, 3 cardioembolism (9.7%) and 1 cerebral venous thrombosis were identified. Six patients had Patent Foramen Ovale. Twenty-two patients reported to experience symptom around landing. Fourteen patients had flight for six hours or longer. Compared to the patients with long flight time (≥6 hrs), those with short flight time had the higher incidence of stroke occurrence around landings (32 vs 68%) and low incidence of unclear stroke onset. Poor outcome, defined as mRS 4 or higher, was associated with old age, unclear stroke onset, and early neurologic deterioration. Conclusion In-flight stroke is uncommon, and can easily be neglected during flight, which result in poor outcome. The stroke risk seems to be relatively high around landing, especially in the travelers with short flight time. The possibility of paradoxical embolism related to motion restriction seems low for stroke occurrence. Old age and unclear stroke onset are associated with poor outcomes.


2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Tom Rivlin ◽  
Eli Pollak ◽  
Randall S. Dumont
Keyword(s):  

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