scholarly journals Experimental Evaluation of an Internally Passively Pressurized Circulation Control Propeller

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jonathan Kweder ◽  
Cale H. Zeune ◽  
Jon Geiger ◽  
Andrew D. Lowery ◽  
James E. Smith
Keyword(s):  
Stagnation Pressure ◽  
Operating Conditions ◽  
Circulation Control ◽  
Trailing Edge ◽  
Lifting Force ◽  
Percent Increase ◽  
Propeller Blades ◽  
Almost All ◽  
And Control ◽  
Do So

The purpose of circulation control for fixed wing aircrafts is to increase the lifting force when large lifting forces and/or slow speeds are required, such as at takeoff and landing. Wing flaps and slats are used on almost all fixed-wing aircraft. While effective in increasing lift, they do so with penalty of increasing drag, weight, and control complexity. The goal of this research was to find an alternative way of pumping pressurized air to the trailing edge slot on a UAV propeller. This design called for rerouting stagnation pressure from the frontal propeller area through the inside of the propeller blades to ejection slots on the trailing edge. This allows for the forward velocity of the aircraft to drive the pressurization of the circulation control plenum passively, without additional hardware. For this study, a Clark-Y airfoil section propeller with an overall diameter of 0.609 meters was designed and tested. The comparison of the augmented to unaugmented propeller showed a 5.12 percent increase in efficiency, which is shown to act over the entire range of flight envelopes of the aircraft and is shown to be particularly beneficial at advance ratios above 0.30, normal operating conditions of propeller-driven UAVs.

2D Parametric Study Using CFD of a Circulation Control Inlet Guide Vane

2007 ◽  
Author(s):  
H. E. Hill ◽  
W. F. Ng ◽  
P. P. Vlachos ◽  
S. A. Guillot ◽  
D. Car
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Circulation Control ◽  
Trailing Edge ◽  
Pressure Losses ◽  
Supply Pressure ◽  
Edge Radius

Circulation control inlet guide vanes (IGVs) may provide significant benefits over current IGVs that employ mechanical means for flow turning. This paper presents the results of a two-dimensional computational study on a circulation control IGV that takes advantage of the Coanda effect for flow vectoring. The IGV in this study is an uncambered airfoil that alters circulation around itself by means of a Coanda jet that exhausts along the IGV’s trailing edge surface. The IGV is designed for an axial inlet flow at a Mach number of 0.54 and an exit flow angle of 11 degrees. These conditions were selected to match the operating conditions of the 90% span section of the IGV of the TESCOM compressor rig at the Compressor Aero Research Laboratory (CARL) located at Wright-Patterson AFB, the hardware that is being used as the baseline in this study. The goal of the optimization was to determine the optimal jet height, trailing edge radius, and supply pressure that would meet the design criteria while minimizing the mass flow rate and pressure losses. The optimal geometry that was able to meet the design requirements had a jet height of h/Cn = 0.0057 and a trailing edge Radius R/Cn = 0.16. This geometry needed a jet to inflow total pressure ratio of 1.8 to meet the exit turning angle requirement. At this supply pressure ratio the mass flow rate required by the flow control system was 0.71 percent of the total mass flow rate through the engine. The optimal circulation control IGV had slightly lower pressure losses when compared with a reference cambered IGV.

How Can Man and Machine Trust Each Other and Work Better Together?

2008 ◽  
Author(s):  
Shuichi Fukuda
Keyword(s):  
Human Error ◽  
Early Stage ◽  
Typical Case ◽  
Operating Conditions ◽  
Know How ◽  
The Past ◽  
Almost All ◽  
Mechanical Objects ◽  
Basic Level ◽  
Do So

Our traditional machines are operated by commands. But Increasing diversification and frequent changes in our environments make it more and more difficult for a designer to foresee the operating conditions. Therefore, designs are shifting from designer-centric to user-centric, because it is a user who knows the situation and can make decisions what he or she should do. So now machines should be designed to help a user understand the current situation better and to help him or her make better decisions. They need more flexibility to work better together with its user. But there are many examples, where although a machine is equipped with a wide variety of functions to cope with almost all sorts of situations, accidents occur due to a human error. Such typical case is CFIT (Controlled Flight into terrain) [1] in airplanes. Norman pointed out that simple mechanical objects can be trusted because their behaviors are so simple people know how to operate them. But machines are getting more and more complicated so a user does not know what to expect from them. And if it does not react to his or her expectations, a user sometimes gets very much emotionally upset and gets panicked. How can we solve this problem? A solution may be found in software development. Software was produced in the past just in the same way as hardware, with their functions fixed. But now software changed its product development style. Software first provides a user with simple functions and once he or she becomes familiar with this basic level of functions, it evolves to a little higher level. Through experience and feedback from a user, software evolves its function gradually and continually. It must be noted that most of our machines are not hardware or software alone. They are combinations of both. So we can develop such a machine which possesses a diversity of functions but reveals at the very early stage of operation a basic level of functions to a user, until he or she gets accustomed to it and puts confidence in it. And when he or she fully experiences this level and desires higher level functions, then the machine evolves. How a user cope with situations varies from user to user, but if a machine is customized this way, a user would trust our machines and would operate with full confidence in them.

scholarly journals Hydraulic Interactions between Injection Events Using Multiple Injection Strategies and a Solenoid Diesel Injector

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3087
Author(s):  
Simón Martínez-Martínez ◽  
Oscar A. de la Garza ◽  
Miguel García-Yera ◽  
Ricardo Martínez-Carrillo ◽  
Fausto A. Sánchez-Cruz
Keyword(s):  
Dwell Time ◽  
Injection Rate ◽  
Operating Conditions ◽  
Multiple Injection ◽  
Rail Pressure ◽  
Injection Strategy ◽  
Fuel Mass ◽  
And Control ◽  
Injection Strategies ◽  
Do So

An experimental study was performed to explore the influence of dwell time on the hydraulic interactions between injection events using pilot injection strategy, split injection strategy, post injection strategy and a solenoid diesel injector. To do so, a sweep of dwell time from 0.55 up to 2 ms using all multiple injection strategies and levels of rail pressure, of 80, 100 and 120 MPa, and single level of back pressure, of 5 MPa, was performed. The hydraulic interactions between injection events were characterized through the second injection hydraulic delay and second injection mass in an injection discharge curve indicator equipped with all the components required for its operation and control. In order to define the operating conditions of the multiple injection strategies, to ensure the same injected fuel mass in all cases, the characteristic curves of injection rate for the solenoid diesel injector studied were obtained. The second injection hydraulic delay increases with dwell time values in the range of 0.55–0.9 ms for all multiple injection strategies and levels of rail pressure tested. Conversely, the second injection hydraulic delay decreases with dwell time values higher than 0.9 ms. Moreover, the second hydraulic delay depends mainly on the dwell time and not on the injected fuel mass during the first injection event. The second injection mass increases with dwell values less than 0.6 ms. By contrast, the second injection mass is not significantly affected by that of the first injection at a dwell time higher than 0.6 ms.

Electron Microscopy of a Herpesvirus Isolated from Marek's Disease in Duck and Chicken Embryo Fibroblast Cultures

1968 ◽  
Vol 26 ◽  
pp. 222-223 ◽  
Author(s):  
Keyvan Nazerian
Keyword(s):  
Inclusion Bodies ◽  
Chicken Embryo Fibroblast ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Duck Embryo Fibroblast ◽  
Multinucleated Cells ◽  
Viral Particles ◽  
Infected Cells ◽  
And Control ◽  
Do So

A herpes-like virus has been isolated from duck embryo fibroblast (DEF) cultures inoculated with blood from Marek's disease (MD) infected birds. Cultures which contained this virus produced MD in susceptible chickens while virus negative cultures and control cultures failed to do so. This and other circumstantial evidence including similarities in properties of the virus and the MD agent implicate this virus in the etiology of MD.Histochemical studies demonstrated the presence of DNA-staining intranuclear inclusion bodies in polykarocytes in infected cultures. Distinct nucleo-plasmic aggregates were also seen in sections of similar multinucleated cells examined with the electron microscope. These aggregates are probably the same as the inclusion bodies seen with the light microscope. Naked viral particles were observed in the nucleus of infected cells within or on the edges of the nucleoplasmic aggregates. These particles measured 95-100mμ, in diameter and rarely escaped into the cytoplasm or nuclear vesicles by budding through the nuclear membrane (Fig. 1). The enveloped particles (Fig. 2) formed in this manner measured 150-170mμ in diameter and always had a densely stained nucleoid. The virus in supernatant fluids consisted of naked capsids with 162 hollow, cylindrical capsomeres (Fig. 3). Enveloped particles were not seen in such preparations.

Convergence in norming and control of modern wireless technologies electromagnetic fields

2020 ◽  
Vol 60 (9) ◽  
pp. 610-613
Author(s):  
Michail Yu. Maslov ◽  
Yuri M. Spodobaev
Keyword(s):  
Wireless Communication ◽  
Electromagnetic Fields ◽  
Communication Systems ◽  
Communication Technologies ◽  
Telecommunications Industry ◽  
High Tech ◽  
Wireless Technologies ◽  
Almost All ◽  
Network Technologies ◽  
And Control

Telecommunications industry evolution shows the highest rates of transition to high-tech systems and is accompanied by a trend of deep mutual penetration of technologies - convergence. The dominant telecommunication technologies have become wireless communication systems. The widespread use of modern wireless technologies has led to the saturation of the environment with technological electromagnetic fields and the actualization of the problems of protecting the population from them. This fundamental restructuring has led to a uniform dense placement of radiating fragments of network technologies in the mudflow areas. The changed parameters of the emitted fields became the reason for the revision of the regulatory and methodological support of electromagnetic safety. A fragmented structural, functional and parametric analysis of the problem of protecting the population from the technological fields of network technologies revealed uncertainty in the interpretation of real situations, vulnerability, weakness and groundlessness of the methodological basis of sanitary-hygienic approaches. It is shown that this applies to all stages of the electromagnetic examination of the emitting fragments of network technologies. Distrust arises on the part of specialists and the population in not only the system of sanitary-hygienic control, but also the safety of modern network technologies is being called into question. Growing social tensions and radio phobia are everywhere accompanying the development of wireless communication technologies. The basis for solving almost all problems of protecting the population can be the transfer of subjective methods and means of monitoring and sanitary-hygienic control of electromagnetic fields into the field of IT.

Drug policy and control at the international level

2018 ◽  
Author(s):  
Thomas F. Babor ◽  
Jonathan Caulkins ◽  
Benedikt Fischer ◽  
David Foxcroft ◽  
Keith Humphreys ◽  
...  
Keyword(s):  
Low Income ◽  
Low Income Countries ◽  
Drug Control ◽  
Prescription Medications ◽  
Access To Treatment ◽  
Illicit Markets ◽  
Pain Medications ◽  
Almost All ◽  
And Control ◽  
Illicit Trafficking

International drug control efforts are designed to coordinate domestic laws with international activities that regulate or limit the supply of psychoactive substances. These efforts are organized around three main drug control treaties that almost all countries have ratified in order to prevent illicit trafficking and other drug-related crime, while at the same time allowing access to prescription medications. The effects of the system have been evaluated mostly in terms of the ability to eliminate illicit markets and supply. The gross imbalance in world consumption of legal opiates is a pointer to the limited availability of effective pain medications in many low-income countries, with 80% of the world’s population having either no or inadequate access to treatment for moderate or severe pain.

scholarly journals Effect of Integrated Neuromuscular Exercise in Physical Education Class on Health-Related Fitness in Female Children

Healthcare ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 312
Author(s):  
Marijana Sinđić ◽  
Draženka Mačak ◽  
Nikola Todorović ◽  
Bianka Purda ◽  
Maja Batez
Keyword(s):  
Physical Education ◽  
Muscular Fitness ◽  
Female Children ◽  
Before And After ◽  
Health Related ◽  
The Republic ◽  
Almost All ◽  
And Control ◽  
Cardiorespiratory Endurance ◽  
Health Related Fitness

Integrated neuromuscular training (INT) showed benefits for improving fundamental movement skills (FMS). However, the INT health-related fitness (HRF) effects are lacking. The current study aimed to determine the effects of INT implemented during physical education (PE) in a primary school in the Republic of Serbia on HRF in female children. The sample consisted of 72 healthy girls who were divided into the intervention (EG: n = 37; mean ± SD: age = 8.17 ± 0.31) and control (CG: n = 35; age = 8.11 ± 0.31) groups. The EG and CG performed the INT program and traditional PE activities two times per week within the first ~15 min of PE class, respectively. The Fitnessgram battery tests assessed the HRF (body composition, cardiorespiratory endurance, muscular fitness, and flexibility) before and after the program. After eight weeks, the EG significantly reduced all fat measures, while the CG decreased only triceps skinfold but to a smaller extent (F = 5.92, p < 0.02, ŋ2 = 0.09). Both groups significantly improved the performance of almost all muscular fitness tests (curl-ups, trunk lift, push-ups); however, the EG increased the push-ups more than the CG (F = 9.01, p < 0.01, ŋ2 = 0.14). The EG additionally improved the modified pull-ups (F = 14.09, p < 0.01, ŋ2 = 0.19) and flexed arm hang (F = 28.82, p < 0.01, ŋ2 = 0.33) tests. The flexibility and cardiorespiratory endurance of both groups did not significantly change after eight weeks. This approach of exercise showed positive acceptance and relatively good results after only eight weeks.

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