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The aerodynamic efficiency of the albatross has always fascinated researchers and the designing of drones mimicking the albatross’s aerodynamic traits have been a major area of interest for the aerospace industry. This review sheds light on the traits behind an albatross’s aerodynamic efficiency such as dynamic soaring, bell shaped lift distribution and provides insights into its hereditary posed encodings and evolutions. The soaring techniques have been introduced and discussed along with the albatross’s morphology and structure which is responsible for its efficiency. In addition, the albatross’s navigational and foraging strategies are briefly discussed to provide a better understanding of the effects of atmospheric conditions on the albatross’s flight characteristics and the limitations.

Application of light emitting diode (LED) is considered to energy saving and increased catches in lift net fisheries. Set lift net fisheries in marine coastal waters of Pangkep used compact fluorescent lamp (CFL) but this lamps consumed high energy and fuels. Application of light emitting diode (LED) is considered to energy saving and increased catches in lift net fisheries. The experimental fishing trial was conducted on 22 July-25 August 2020 in marine coastal waters of Pangkep, Makassar Strait, Indonesia. The study using 1 units of set lift net with LED as light attractor. The result of study show that The fishes catch consist of main catch 149.21 kg (67.73 %), by catch 37.28 kg (16.93 %), and discard catch 43.76 kg (19.86 %).

The spatial distribution of lift net (bagan) and the impact on the Sardinella lemuru (lemuru) catches in Senggrong bay - Banyuwangi has been analysed. The data used in this study consists of Pleiades satellite data, aerial photographs of unmanned aerial vehicle (UAV) or drones and in situ measurements in the same period. Fishery data during 2013 to 2017 were analysed to determine the variability of Lemuru catches. The analysis of bagan spatial distribution was performed using visual interpretation technique. Spatial distribution of bagan was analyzed by overlaying data at different period. The results show that the number of bagan in Senggrong bay were 85 unit and spread evenly throughout the bay. In the northwest monsoon, the bagan were spreadedin the northern part of the bay, while in the southeast monsoon, the bagan were shifted to the south due to the high waves and wind speed. Lemuru spawning time was occured in May – July. During spawning time, the amount of Lemuru catches by bagan was relatively low. The peak of lemuru catch was occurred in the period of October to January. The impact of bagan on the decreasing of lemuru abundance is relatively low.

Whale shark tourism is a growing industry in the world. This study aimed to determine the benefits local people earn from whale shark tourism at two sites in Indonesia, Botubarani in Gorontalo Province and Labuhan Jambu, Teluk Saleh, Nusa Tenggara Barat Province. This study involved dive centres, fishermen, community tourism groups, village enterprises (BUMDES), home stay owners, car rental companies, boat owners, lift net owners, snorkelling equipment rental businesses and ecotourism operators. In Botubarani, dive centres sold whale shark watching dive trips for US$42.3/pax, and snorkelling trips for US$23/pax, of which, US$4.6 and US$2.7 went to the Pokdarwis, and US$33.5 to the dive centre. For nondivers, trips cost US$11.5, of which US$1.5 was for whale shark bait, US$1.5 went to the Pokdarwis, and US$4.6 to fishermen. Whale shark watchers in Labuhan Jambu paid US$211.5-US$270 to ecotourism operators plus US$7.7/pax to the BUMDES. From that money, US$119 was paid to lift net owners, US$42 to boat operators, and US$19.2-US$76.9 to ecotourism operators. On average, car rental companies received US$46.1, home stays received US$7.6, and US$11.5 was paid for rental equipment.

The Caspian Sea, which is known as the largest lake in the world, is located in the northern part of Iran. Caspian Sea Sprat or Clupeidae are pelagic fish and play an important role in the food chain. In Iran, clupeid fish are caught by a conical lift net with artificial light and at night. The color of artificial light used in the conical lift net is white or sunny. In a study conducted from May 2018 to January 2019 in the fishing port of Amirabad, the effect of two types of artificial light (blue and red light) was investigated. For this purpose, two lamps with a color of blue and red with the same Volt and Ampere of white light were used in the depth of 40 – 50 meters. The results show a significant difference in the average length of sprat fish caught in each of the lights used (p

Various types of fishing gear operated in Lada Bay waters. Data and information regarding fixed or static fishing gear (SFG) are minimal. This research aims to (1) determine the number and size of SFG; and (2) mapping the fishing ground of SFG in Lada Bay. The census method was conducted from August 2018 to April 2019. The identification of SFG and water characteristics were analyzed descriptively. Map of the fishing ground made with GIS. The number of SFG in Lada Bay was 123 units (45 units of fixed lift net and 78 units of the arrier). The fixed lift net sizes range from 10.6-12.7 m with bamboo and areca trees construction. The leader net of the barrier is 100 m, wings 37.5 m, body 10.5 m, and crib 4x4-4x5 m, with bamboo and nets construction. The fishing ground of the fixed lift net is from Tanjung Lesung to the north of Liwungan Island. While the barrier is from Tanjung Lesung to Ciseukeut River. Water characteristics for fixed lift net are temperature 27.2-29°C, pH 7.7-9, salinity 30-33 ppt, depth 11-16 m, and brightness 2.8-3.8 m. The water condition for barriers is temperature 27.3-30°C, salinity 30-34 ppt, current 0.1-0.3 m/s, and depth 1.3-7.7 m with the substrate of muddy sand and sandy coral.

Central Tapanuli Regency is one of the regions in North Sumatra that has fishery potential. In Hajoran, the livelihoods of most people as fishermen are on bamboo platform lift net fishing gear. Bamboo platform lift net is a fishing gear that catches small pelagic fish and is installed permanently. The factor of the installation of a bamboo platform lift net at a different depth will affect the income earned by each fisherman. The purpose of this study was to compare the catches of fish that were predominantly caught on a bamboo platform lift net based on different depths. This research was conducted in February 2020 at Hajoran Village, Central Tapanuli regency in Sibolga City, by using a survey method. Data collection was carried out by directly recording the catches 3 units of bamboo platform lift net and then comparing the three results by using One Way ANOVA analysis. The results showed that the amount of catch per lift net varies, depending on the type of fish and its depth. For pony fishes, species were more commonly found at a depth of 30 M with a total of 5.5 kg, while fringescale sardine and anchovies were found at a depth of 36 M with a total of 10.6 kg and 64.4 kg, respectively. One Way ANOVA revealed that there was a significant difference found on fringescale sardine and ponyfish in term of water depth (p < 0.05), while there was no any significant different on anchovy fish (p < 0.05).

The wing profile for Micro Air Vehicle (MAV) can be easily developed through the polynomial equation method which is proven in generating good aerodynamic performances. However, the study demands more studies in profile configurations to provide more evidence which interrelated with its aerodynamic performances. Thus, in this works, an aerodynamic study on different wing profiles configurations has been carried out. Profile 1, Profile 2 and Profile 3 were developed through the 3rd order polynomial equations have analyzed based on simulation works by using ANSYS-CFX. Based on the lift distribution analysis, it shows that Profile 3 has a huge advantage in generating better lift distribution (CL) among the wing profiles. Profile 3 able to produce at least 20% to 22.9% better maximum lift coefficient (CLmax) and CL magnitude compared to the other wing profiles. Despite its benevolent in CL performances, Profile 3 has induced the highest drag (CD) penalty among the wing profiles. Profile 3 has consistently produced at least 57.5% higher CD magnitude compared to other wing profiles. However, in terms of moment coefficient (CM) performances, Profile 3 has shown a promising ability in providing better wing stability compared to the other wing profile due to steeper CM slope.

Banten Bay is the main fishing ground for small scale fishing activity in Banten Province. The fishers use several fishing gears, such as gillnet, trap, hook and line, danish seine, and lift net. However, a lift net fishery has a significant contribution to fish production in Archipelagic Fishing Port of Karangantu, Serang City. The purpose of this study is to analyze the status of fixed lift net fishing in Banten Bay. The research was conducted on Mei to July 2019 through survey and field observation. There are more than 150 units of fixed lift net operated in Banten Bay, that have landing place in Karangantu and Panjang Island. The rectangle lift nets (10Wx10L m2) are fixed at six to ten-meter depth. The fishers used four to six pressure kerosene lamps as a light source before 2010. However, since 2010 the fishers changed the lamp to the electrical light source due to high price, and limited availability of kerosene. In peak season, the lift nets have high productivity (500-1000 kg/trip). The productivity was decreased in the low season (< 100 kg/trip). The main target species in fixed lift net fishing are anchovies and squids with a potential margin more than IDR 60 million per year.

The crucial thing in lift net is fishing equipments such as lamps, generator and roller as supporting the fishing operations activities. The less function of that fishing equipments can be affect to the caught. The development of fishing equipment in lift net is important to increase the production of caught. This study aim to find out the development strategies of lift net fishing equiment in Krueng Raya. The strategies development of fishing equipment will be analyzed by using analytic hierarchy process (AHP) based on interviewed with respondents, they are fisherman, panglima laot, and Department of Marine and Fisheries of Aceh. The result showed that the strategy development of fishing equipment in lift net in Krueng Raya is prioritized to modernizing of fishing equipment (0,579) with total consistency ratio 0,04.

Lift-net (local term: Bagan Rambo) is one of the most productive fishing gear in the coastal community of Gulf of Bone, including those in the Bone District. This study aims to explain the characteristics of the marketing channels of frigate tuna caught by fishermen and the effectiveness and efficiency of frigate tuna market system. The study was conducted from December 2017 to February 2018 at Bone District, South Sulawesi Province-Indonesia with a purposive sampling method of 37 units of lift-net and 481 fisheries households. The results of the study show that lift-net owners and fishmongers are the main channels of catch marketing (66.7%). For Bone sub-district of Tanete Riattang Timur 50% of catches go fishing auction and fisheries companies. The effective marketing system of frigates tuna are: 1) fishermen get more profit if they sell their catch in kg instead of selling per bucket, 2) the boat owner and fishmonger get a big profit, at the sale of a minimum price. The effective marketing channel is directly selling catches to fisheries companies.

Aircraft icing has influence on the preliminary safety and performance evaluation of airplane. In this paper, based on different ice shapes (none, rime, mixed), the aerodynamic models of airfoil are established to analyze. Various lift/drag characteristics are obtained by numerical simulation using computational fluid dynamics (CFD) under different icing conditions. Navier-Stokes (N-S) equation and Spalart-Allmaras (S-A) turbulence model are adopted. The results show: 1. It’s obvious that lift-drag characteristics are different under various ice shapes. The lift coefficient (α=0° ∼7°): CL none>CL rime>CL mixed, the drag coefficient (α=0° ∼7°): CD nonerimemixed. 2. At the same angle of attack (α=6°), lift/drag characteristics in the condition of different ice shapes are different. The pressure gradient at the leading edge is ▽p none>Vp rime>▽p mixed, which has important effect on the speed of airstream flow and the flow separation at the front zone of airfoil.

This paper presents a systematic experimental investigation on a passive flow control of a NACA0012 airfoil using real feather flap which is installed on the pressure surface. The focus of the present study is to determine the major role of a real feather flap in the aerodynamic performance of a NACA0012 airfoil at small attack angles (α). The feather flap width w and its installation position xin are varied from 0.27c to 0.8c and from 0.0 to 0.2c, respectively, where xin is measured from the leading edge of the airfoil, and c is the chord length of the airfoil. Detailed Particle Image Velocimetry (PIV) measurements are conducted to understand the origin of the aerodynamic benefits introduced by the feather flap. When mounted on the pressure side, the feather flap is proved to be beneficial to improve the aerodynamic performance of the airfoil at small α (= −4° to 8°). The lift CL and lift-to-drag ratio CL/CD are enhanced by 186% and 72%, respectively, for w = 0.53c, xin = 0.2c at α = 2°. Time-averaged vorticity and streamwise velocity around the flapped airfoil weaken and decrease, respectively, compared with those around the plain airfoil, which are attributed to the increased CL and CL/CD.

A high-lift configuration of the civil aircraft including body, wing in high-lift configuration, nacelle with pylon and empennage is considered in the present work. Numerical simulations of the flow have been carried out in the framework of Reynolds averaged Navier-Stokes (RANS) equations for low subsonic Mach number. The active flow control method, which is capable to improve maximal lift of the aircraft, has been considered. The influence of jet blowing near wing-body junction on aerodynamic characteristics has been investigated.

The clap-and-fling effect, first observed in a number of insects, serves as a lift-enhancing mechanism for bio-inspired flapping wing micro aerial vehicles (MAV). In our comprehensive literature survey, we observe that the effect manifests differently in insects and contemporary MAVs; insects have active control over the angle of attack and stroke plane of the wing, whereas a number of kinematic parameters of an MAV's flexible wings are determined passively. Although there is consensus that flinging motion significantly enhances aerodynamic lift, the effect of clapping motion is not well-studied. To address this gap, we experimentally quantify the contribution of clapping motion using force measurement and particle image velocimetry. No significant enhancement in lift was observed due to clapping motion, because the momentum jet was too weak. However, the kinematics and flow conditions in our study were notably different from those in the previous studies on insect models. The wings of the MAV are flexible, and deform passively. Hence, the clapping of the trailing edges, and the appearance of a trailing edge momentum jet, was delayed and significantly suppressed. Using force measurement and CFD simulations, it was also found that the lesser the distance between the leading edges of the wings at the end of clap, the higher is the lift due to the subsequent fling.

Some apparently confusing aspects of Newton's laws as applied to an aircraft in normal horizontal flight are neatly resolved by a careful analysis of force, momentum, energy and power. A number of related phenomena are explained at the same time, including the lift and induced drag coefficients, used empirically in the aviation industry.

We measured the wing kinematics of fruitflies in both vertically-ascending and hovering flights and studied the aerodynamic forces and power in the two flight modes. The average ascending velocity is 0.45 m s-1; the stroke plane angle and the stroke frequency are the same as that in hovering flight, whilst the stroke amplitude is increased by 12% and the wing angle of attack in the latter half of a down- and upstroke both increased by 10%. Flow analysis shows that during ascending, the flies experience a downward inflow which reduces the effective angle of attack considerably. This problem is overcome by the increases in the stroke amplitude and the angle of attack, which result in a larger wing drag. As a result, the power at ascending is increased by 36% over that at hovering. Two very interesting observations were made. (1) Using the same power, level-forward flight can be about four times as fast as ascending flight. (2) Power for ascending flight is the same as that for carrying a load about 27% of the insect's weight at hovering.

In any conventional aircraft the wings provide the lift and the engines provide the thrust. In a bird, however, the wings have to provide the thrust as well as the lift. In this article we shall use the ideas presented in the first article of this series to develop a simple theory to explain how this comes about, and use it to predict some important characteristics of the flight of birds, including their wingbeat patterns and their minimum power requirements.

Half-Rotating Wing (HRW) is a new kind of flapping wing system with rotating flapping instead of oscillating flapping. Estimating approach of hovering lift which generated in hovering flight was important theoretical foundation to design aircraft using HRW. The working principle of HRW based on Half-Rotating Mechanism (HRM) was firstly introduced in this paper. Generating process of lift by HRW was also given. The calculating models of two lift mechanisms for HRW, including Lift of Flow Around Wing (LFAW) and Lift of Flow Dragging Wing (LFDW), were respectively established. The lift estimating model of HRW was further deduced, by which hovering lift for HRW with different angular velocity could be calculated. Case study using XFLOW software simulation indicates that the above estimating method was effective and feasible to predict roughly the hovering lift for a new HRW system.

Because the classical explanation for flight seems so distant from our experience an alternative `momentum flux change' explanation has often been didactically employed. We review the way in which lift on a moving airfoil arises and then show how the `momentum flux change' argument arises as the result of taking a particular limit of the momentum flux equations. We thus see where the latter may be used. Finally, we suggest a novel way of introducing the concept of lift, which allows a more direct experience of the fluid element.

This book is a pithy defence of science against various undesirable tendencies: post-modernism, religious fundamentalism and relativism. It is highly readable. It is also rather silly.

Nature's flapping-wing flyers are adept at negotiating highly turbulent flows across a wide range of scales. This is in part due to their ability to quickly detect and counterract disturbances to their flight path, but may also be assisted by an inherent aerodynamic property of flapping wings. In this study, we subject a mechanical flapping wing to replicated atmospheric turbulence across a range of flapping frequencies and turbulence intensities. By means of flow visualization and surface pressure measurements, we determine the salient effects of large-scale freestream turbulence on the flow field, and on the phase-average and fluctuating components of pressure and lift. It is shown that at lower flapping frequencies, turbulence dominates the instantaneous flow field, and the random fluctuating component of lift contributes significantly to the total lift. At higher flapping frequencies, kinematic forcing begins to dominate and the flow field becomes more consistent from cycle to cycle. Turbulence still modulates the flapping-induced flow field, as evidenced in particular by a variation in the timing and extent of leading edge vortex formation during the early downstroke. The random fluctuating component of lift contributes less to the total lift at these frequencies, providing evidence that flapping wings do indeed provide some inherent gust mitigation.

In your feature "Stairway to the heavens", which examines progress towards building a "space elevator" that could take astronauts from the surface of the Earth into space (December 2011 pp30–34), I am quoted as dismissing the merits of building a similar structure on the surface of the Moon. My comments do not, however, impart quite what I intended.

DASH+Wings is a small hexapedal winged robot that uses flapping wings to increase its locomotion capabilities. To examine the effects of flapping wings, multiple experimental controls for the same locomotor platform are provided by wing removal, by the use of inertially similar lateral spars, and by passive rather than actively flapping wings. We used accelerometers and high-speed cameras to measure the performance of this hybrid robot in both horizontal running and while ascending inclines. To examine consequences of wing flapping for aerial performance, we measured lift and drag forces on the robot at constant airspeeds and body orientations in a wind tunnel; we also determined equilibrium glide performance in free flight. The addition of flapping wings increased the maximum horizontal running speed from 0.68 to 1.29 m s⁻¹, and also increased the maximum incline angle of ascent from 5.6° to 16.9°. Free flight measurements show a decrease of 10.3° in equilibrium glide slope between the flapping and gliding robot. In air, flapping improved the mean lift:drag ratio of the robot compared to gliding at all measured body orientations and airspeeds. Low-amplitude wing flapping thus provides advantages in both cursorial and aerial locomotion. We note that current support for the diverse theories of avian flight origins derive from limited fossil evidence, the adult behavior of extant flying birds, and developmental stages of already volant taxa. By contrast, addition of wings to a cursorial robot allows direct evaluation of the consequences of wing flapping for locomotor performance in both running and flying.

We explore the implementation of wing feather separation and lead-lagging motion to a flapping wing. A biomimetic flapping wing system with separated outer wings is designed and demonstrated. The artificial wing feather separation is implemented in the biomimetic wing by dividing the wing into inner and outer wings. The features of flapping, lead-lagging, and outer wing separation of the flapping wing system are captured by a high-speed camera for evaluation. The performance of the flapping wing system with separated outer wings is compared to that of a flapping wing system with closed outer wings in terms of forward force and downward force production. For a low flapping frequency ranging from 2.47 to 3.90 Hz, the proposed biomimetic flapping wing system shows a higher thrust and lift generation capability as demonstrated by a series of experiments. For 1.6 V application (lower frequency operation), the flapping wing system with separated wings could generate about 56% higher forward force and about 61% less downward force compared to that with closed wings, which is enough to demonstrate larger thrust and lift production capability of the separated outer wings. The experiments show that the outer parts of the separated wings are able to deform, resulting in a smaller amount of drag production during the upstroke, while still producing relatively greater lift and thrust during the downstroke.

Russia is set to launch a radio telescope into orbit that will let astronomers peer more clearly into space than ever before.

Given sufficient space, it is possible for gliding animals to reach an equilibrium state with no net forces acting on the body. In contrast, every gliding trajectory must begin with a non-steady component, and the relative importance of this phase is not well understood. Of any terrestrial animal glider, snakes exhibit the greatest active movements, which may affect their trajectory dynamics. Our primary aim was to determine the characteristics of snake gliding during the transition to equilibrium, quantifying changes in velocity, acceleration, and body orientation in the late phase of a glide sequence. We launched 'flying' snakes (Chrysopelea paradisi) from a 15 m tower and recorded the mid-to-end portion of trajectories with four videocameras to reconstruct the snake's body position with mm to cm accuracy. Additionally, we developed a simple analytical model of gliding assuming only steady-state forces of lift, drag and weight acting on the body and used it to explore effects of wing loading, lift-to-drag ratio, and initial velocity on trajectory dynamics. Despite the vertical space provided to transition to steady-state gliding, snakes did not exhibit equilibrium gliding and in fact displayed a net positive acceleration in the vertical axis, an effect also predicted by the analytical model.

Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound (~0.3 kg) and small birds with rounded wings do not use intermittent glides.

The US House of Representatives began hearings last month with the aim of reducing export controls on commercial satellite technology. Fulfilling a campaign promise, the Obama administration is encouraging Congress to amend a decade old law that defines commercial satellites as weapons. The amendment would allow US satellite firms to increase sales abroad, particularly to China.

On or shortly after 11 January, an AtlasV rocket is due to lift off from Cape Canaveral carrying a NASA spacecraft to the outer reaches of the solar system. Its destination is the Kuiper Belt – the disc-shaped region of rocky objects that includes the planet Pluto and its moon Charon. The New Horizons craft should reach Pluto in 2015.