The Aerodynamic Forces Associated with Harmonic Motion of Slender Wings on Stationary Bodies of Revolution

1960 ◽  
Vol 11 (4) ◽  
pp. 355-370
Author(s):  
R. D. Milne
Keyword(s):  
Vertical Plane ◽  
Cross Flow ◽  
Deformation Mode ◽  
The Body ◽  
Control Surface ◽  
Aerodynamic Forces ◽  
Slender Body Theory ◽  
Bodies Of Revolution ◽  
Control Plan ◽  
And Control

SummaryThe slender-body theory is applied to the determination of the unsteady aerodynamic forces on slender wing-body combinations when the body is stationary and the wing is deforming harmonically. The uniform body is circular in cross section, the wings are placed symmetrically and the wing deformation mode is necessarily symmetrical about a vertical plane through the body axis. The frequency parameter is restricted to that range for which the “cross-flow” potential equation is Laplace's equation. The case of an allmoving slender control surface on a body is treated in detail and numerical results are given for the forces and moments on body and control surface when the control plan form is triangular: the presence of a gap is neglected.

Line source distributions and slender-body theory

1963 ◽  
Vol 17 (2) ◽  
pp. 285-304 ◽  
Author(s):  
John P. Moran
Keyword(s):  
Potential Flow ◽  
Line Source ◽  
The Body ◽  
Successive Approximations ◽  
External Disturbances ◽  
Slender Body Theory ◽  
Bodies Of Revolution ◽  
Plane Flow ◽  
Body Theory

A systematic procedure is presented for the determination of uniformly valid successive approximations to the axisymmetric incompressible potential flow about elongated bodies of revolution meeting certain shape requirements. The presence of external disturbances moving with respect to the body under study is admitted. The accuracy of the procedure and its extension beyond the scope of the present study—e.g. to problems in plane flow - are discussed.

How animals glide: from trajectory to morphology

2015 ◽  
Vol 93 (12) ◽  
pp. 901-924 ◽  
Author(s):  
John J. Socha ◽  
Farid Jafari ◽  
Yonatan Munk ◽  
Greg Byrnes
Keyword(s):  
Performance Metrics ◽  
Flapping Flight ◽  
The Body ◽  
Aquatic Environments ◽  
Aerodynamic Forces ◽  
Relative Ease ◽  
Ecological Roles ◽  
And Control ◽  
Glide Paths

Animals that glide produce aerodynamic forces that enable transit through the air in both arboreal and aquatic environments. The relative ease of gliding compared with flapping flight has led to a large diversity of taxa that have evolved some degree of flight capability. Glide paths are curved, reflecting the changing forces on the animal as it progresses through its aerial trajectory. These changing forces can be under control of the glider, which uses specific aspects of anatomy to modulate lift, drag, and rotational moments on the body. However, gliders share no single anatomical or behavioral feature, and some species are unspecialized for gliding, producing aerodynamic forces using posture and orientation alone. Animals use gliding in a broad range of ecological roles, suggesting that multiple performance metrics are relevant for consideration, but we are only beginning to understand how gliders produce and control their flight from takeoff to landing. In this review, we focus on the physical aspects of how glide trajectories are produced, and additionally discuss the range of morphologies and postures that are used to control aerial movements across the broad diversity of animal gliders.

Modeling and Control of a Micro Flapping Wing Rotor

2014 ◽  
Vol 635-637 ◽  
pp. 1360-1363 ◽  
Author(s):  
Yan Fang Hang ◽  
Jing Lu ◽  
Ying Jun Hu
Keyword(s):  
Output Feedback Control ◽  
Open Loop ◽  
Flapping Wing ◽  
The Body ◽  
Control Surface ◽  
Flight Performance ◽  
Design Decisions ◽  
Modeling And Control ◽  
Simulation Testing ◽  
And Control

The system of Micro Flapping-wing Rotor to achieve the flapping and rotation motions is first introduced briefly. Then the system dynamic model which includes the flapping rotary flight aerodynamics at a low Reynolds number regime, the body dynamics, the electromagnetic actuator and the control surface is described. This model and system simulation in the preliminary design phase may provide the opportunity for designers to make fundamental design decisions early to improve the flight performance. Also, the simulator is used to study open loop flight dynamics and test a periodic proportional output feedback control law. Simulation testing shows that the control system has a good flight performance for this flapping wing rotor.

Supersonic Flow Past Slender Bodies With Discontinuous Profile Slope

1955 ◽  
Vol 6 (2) ◽  
pp. 114-124 ◽  
Author(s):  
L. E. Fraenkel ◽  
H. Portnoy
Keyword(s):  
Internal Flow ◽  
Leading Edge ◽  
Rate Of Change ◽  
The Body ◽  
Cross Sectional ◽  
Slender Body Theory ◽  
Bodies Of Revolution ◽  
Slender Bodies ◽  
External Forces ◽  
Sectional Shape

SummaryWard’s slender-body theory is extended to derive first approximations to the external forces on slender bodies of general cross section with discontinuous profile slope. Two classes of body are considered: bodies whose profile (typified by the local radius) is continuous between the nose and base, and certain bodies whose profile is discontinuous, such as bodies with annular or side air intakes and wing-bodies on which the wing has an unswept leading edge. (Where air intakes are concerned, it is assumed that they are sharp-edged and that there is no “ spillage ” of the internal flow).The following conclusions apply to the former class of bodies. The variation of drag with Mach number is found to depend only on the discontinuities in the longitudinal rate of change of the cross-sectional area, and is thus independent of cross-sectional shape. The drag itself is unchanged if the direction of the flow is reversed. The expressions for lift and moment assume the same forms as for smooth pointed bodies, the lift depending only on conditions at the base of the body.The general theory is applied to winged bodies of revolution with an unswept wing leading edge: the results bear a marked resemblance to those obtained by Ward. The results for wings alone are seen to be applicable, with one modification, to subsonic as well as to supersonic speeds.

scholarly journals Cavity flow past a slender pointed hydrofoil

1961 ◽  
Vol 11 (2) ◽  
pp. 187-208 ◽  
Author(s):  
E. Cumberbatch ◽  
T. Y. Wu
Keyword(s):  
Angle Of Attack ◽  
Cross Flow ◽  
The Body ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Slender Body Theory ◽  
Flow Past ◽  
Two Dimensional Flow ◽  
Cavity Boundary ◽  
The Cross

A slender-body theory for the flow past a slender, pointed hydrofoil held at a small angle of attack to the flow, with a cavity on the upper surface, has been worked out. The approximate solution valid near the body is seen to be the sum of two components. The first consists of a distribution of two-dimensional sources located along the centroid line of the cavity to represent the variation of the cross-sectional area of the cavity. The second component represents the cross-flow perpendicular to the centroid line. It is found that over the cavity boundary which envelops a constant pressure region, the magnitude of the cross-flow velocity is not constant, but varies to a moderate extent. With this variation neglected only in the neighbourhood of the hydrofoil, the cross-flow is solved by adopting the Riabouchinsky model for the two-dimensional flow. The lift is then calculated by intergrating the pressure along the chord; the dependence of the lift on cavitation number and angle of attack is shown for a specific case of the triangular plan form.

Calculation of Subsonic Normal Force and Centre of Pressure Position of Bodies of Revolution Using a Slender Body Theory – Boundary Layer Method

1980 ◽  
Vol 31 (1) ◽  
pp. 1-25
Author(s):  
K.D. Thomson
Keyword(s):  
Boundary Layer ◽  
Velocity Distribution ◽  
Normal Force ◽  
The Body ◽  
Slender Body ◽  
Centre Of Pressure ◽  
Slender Body Theory ◽  
Bodies Of Revolution ◽  
Slender Bodies ◽  
Body Theory

SummaryThe aim of this paper is to present a method for predicting the aerodynamic characteristics of slender bodies of revolution at small incidence, under flow conditions such that the boundary layer is turbulent. Firstly a panel method based on slender body theory is developed and used to calculate the surface velocity distribution on the body at zero incidence. Secondly this velocity distribution is used in conjunction with an existing boundary layer estimation method to calculate the growth of boundary layer displacement thickness which is added to the body to produce the effective aerodynamic profile. Finally, recourse is again made to slender body theory to calculate the normal force curve slope and centre of pressure position of the effective aerodynamic profile. Comparisons made between predictions and experiment for a number of slender bodies extending from highly boattailed configurations to ogive-cylinders, and covering a large range of boundary layer growth rates, indicate that the method is useful for missile design purposes.

A Combination of the Quasi-Cylinder and Slender Body Theories

1955 ◽  
Vol 59 (532) ◽  
pp. 305-308 ◽  
Author(s):  
C. H. E. Warren ◽  
L. E. Fraenkel
Keyword(s):  
Point Of View ◽  
The Body ◽  
Slender Body ◽  
Maximum Diameter ◽  
Slender Body Theory ◽  
Bodies Of Revolution ◽  
Pressure Distributions ◽  
Simple Body ◽  
Body Theory ◽  
Supersonic Flow Past Bodies

The Quasi-Cylinder and slender body theories for the supersonic flow past bodies of revolution have been much used in recent years because, for reasonably simple body profiles, these theories permit a simple and rapid calculation of the first-order pressure distributions and aerodynamic forces. It is assumed in both theories that the body profile slope is small; in the quasi-cylinder theory it is also assumed that the body radius is nearly constant, whereas in the slender body theory it is assumed that the thickness ratio of the body (maximum diameter/length) is small.In the present note these two theories are combined completely. From a strictly mathematical point of view nothing is gained by this combination, and, furthermore,application of the combined theory to a particular case is in general a little more laborious than application of either of the original theories.

Perbandingan Efek Suplementasi Tablet Tambah Darah Dengan Dan Tanpa Vitamin C Terhadap Kadar Hemoglobin Pada Ibu Hamil Dengan Usiakehamilan 16-32 Minggu Di Desa Keniten Kecamatan Mojo Kabupaten Kediri

2017 ◽  
Vol 3 (1) ◽  
pp. 76
Author(s):  
Siti Asiyah ◽  
Dwi Estuning Rahayu ◽  
Wiranti Dwi Novita Isnaeni
Keyword(s):  
Treatment Group ◽  
Vitamin C ◽  
Gestational Age ◽  
Group Treatment ◽  
Sampling Technique ◽  
Hemoglobin Level ◽  
The Body ◽  
Control Group ◽  
Fetal Organ ◽  
And Control

The needed of Iron Tablet in pregnancy was increase than mother who not pregnant.  That  cause of  high metabolism at the pregnancy for formed of  fetal organ and energy. One of effort for prevent anemia in mother pregnant with giving the Iron tablet and vitamin c. The reason of  this research in 4 June – 11 July 2014 is for compare the effect of  iron tablet suplementation with and without vitamin C toward Hemoglobin level in mother pregnant With Gestational Age Of 16-32 Weeks In Desa Keniten Kecamatan Mojo Kabupaten Kediri. This research method using comparative analytical.  Research design type of Quasy Eksperiment that have treatment group and control group. Treatment group will giving by Iron tablet and 100 mg vitamin C, and control group just giving by iron tablet during 21 days. Population in this research are all of mother pregnant with Gestational Age Of 16-32 Weeks with Sampling technique is  cluster random sampling is 29 mother pregnant. Comparison analysis of  iron tablet suplementation effect with and without vitamin C toward Hemoglobin level in mother pregnant With Gestational Age Of 16-32 Weeks, data analysis using Mann Whitney U-test and the calculated U value (44,5) less than U-table (51). So there was difference of iron tablet suplementation effect with and without vitamin C toward Hemoglobin level in mother pregnant With Gestational Age Of 16-32 Weeks Therefore, the addition of vitamin C on iron intake is needed to increase the uptake of iron tablets. When the amount of iron uptake increases, the reserves of iron in the body will also increase, so as to prevent anemia in pregnant women; Keywords : Iron Tablet (Fe), Vitamin C, Hemoglobin level, Mother Pregnant

In-vivo evaluation of lipid lowering ability of Chloris paraguaiensis extracts

2020 ◽  
Vol 7 (2) ◽  
pp. 21-24
Author(s):  
Pavani C H
Keyword(s):  
Medicinal Plants ◽  
Chemical Constituents ◽  
The Body ◽  
Lipid Lowering ◽  
Medical Systems ◽  
In Vivo Evaluation ◽  
Standard Drug ◽  
Anti Oxidant ◽  
And Control

Hyperlipidemia is the immediate results of the excessive fat intake in food. This results in the elevated levels of cholesterol and triglycerides in the blood. This leads to heart conditions like CAD, hypertension, congestive heart failure as risk factors which can be lethal. There are many drugs to treat and control the lipids levels in the body. These drugs are either designed to prevent LDL accumulation and VLDL synthesis. Some drugs also lower the elevated levels of saturated lipids in the body. But many drugs are known to cause side effects and adverse effects; therefore, alternatives to the drugs are the subjects for current investigations. Herbs and medicinal plants are used as treatment sources for many years. They have been used in the Indian medical systems like Ayurveda, Siddha etc. As the application of herbs in the treatment is growing, there is an urgent need for the establishment of Pharmacological reasoning and standardization of the activity of the medicinal plants. Chloris paraguaiensis Steud. is Poyaceae member that is called locally as Uppugaddi. Traditionally it is used to treat Rheumatism, Diabetes, fever and diarrhoea. The chemical constituents are known to have anti-oxidant properties and most of the anti-oxidants have anti-hyperlipidemic activity too. Since the plant has abundant flavonoid and phenol content, the current research focusses on the investigation of the anti-hyperlipidemic activity of the plant Chloris extracts. Extracts of Chloris at 200mg/kg showed a comparably similar anti hyperlipidemia activity to that of the standard drug. The extracts showed a dose based increase in the activity at 100 and 200mg/kg body weight.

Role of Rasayana in Prevention of COVID-19 - A Review

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 716-722
Author(s):  
Sneha Dhakite ◽  
Sadhana Misar Wajpeyi
Keyword(s):  
Immune System ◽  
Respiratory System ◽  
Viral Infections ◽  
Cost Effective ◽  
The Body ◽  
Healthy Life ◽  
Vital Functions ◽  
Healthy Life Style ◽  
And Control

The “Coronavirus disease 19 (COVID-19)” is caused by “Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)”, a newly discovered member of the Coronaviridae family of viruses which is a highly communicable. There is no effective medical treatment till date for Coronavirus disease hence prevention is the best way to keep disease away. Rasayana proved to be highly efficacious and cost effective for the Prevention and Control of viral infections when vaccines and standard therapies are lacking. Rasayana Chikitsa is one of the eight branches of Ashtanga Ayurveda which helps to maintain healthy life style. Rasayana improves immunity and performs many vital functions of human body. Vyadhikshamatva that is immune mechanism of the body is involved in Prevention of the occurrence of a new disease and it also decreases the virulence and progression of an existing disease. In COVID-19 the Respiratory system mainly get affected which is evident from its symptoms like cold, cough and breathlessness. Here the drugs help in enhancing immune system and strengthening functions of Respiratory system can be useful. For this purpose, the Rasayana like Chyavanprasha, Agastya Haritaki, Pippali Rasayana, Guduchi, Yashtimadhu, Haridra, Ashwagandha, Tulsi are used. Rasayana working on Respiratory system are best for Prevention of Coronavirus and boosting immune system. Rasayana Chikitsa can be effective in the Prevention as well as reducing symptoms of COVID-19.

Sign in / Sign up

Export Citation Format

Share Document