For fixedwing aircraft, ground effect is the increased lift and decreased aerodynamic drag that an aircrafts wings generate when they are close to a fixed surface. Dave gee demonstrates how to modify a stock rubber powered model, including stretch winding the motor for better flight performance and holding a. Vural 5 the student must note that fitting process shown in fig. Especially if flaps are engaged, you want to be careful not to slow the model down too much or you will hit stall speed. Found that our model ground effect glider had poor pitch stability due to the tail providing positive lift rather than negative lift. Dec 05, 2007 another model was the lunclass, entering service with the black sea fleet in 1987. The basic design principle is that the closer the wing operates to an external surface such as the ground, when it is said to be in ground effect, the more efficient it becomes. As your model gets closer to the landing spot you want to gradually reduce power to help the plane settle and break through ground effect, a phenomenon close to the ground that wants to keep your model flying. The winglets are both side i drawn one of then apart to show the correct dimensions and are mounted at 45 degrees, but i am not sure if they are really needed, will try without then next time.
What is the effect of uneven ground on ground effect. For decades the russians have experimented with aircraft they called wig wing in ground effect planes. Inaddition to measurements ofdrag, thespeed distribution nearthe ground plane wasmeasured for two types of leading edge. For aircraft that operate in free air this makes sense, but in ground effect the shape of the lower side of the wing is very important. Ground effect in fixed wing aircraf occurs as approach ground in both takeoff and landing situations in fixed wing aircraf, ground effect is the increased lif and decreased drag an aircraf experiences as it approaches a fixed surface when an aircraf reaches a distance ground, the induced drag due to lif is greatly reduced due to the reduction in the induced downwash. Stability concepts rc model aircraft and aerodynamics. May 03, 2015 a problem with ground effect is that staying in ground effect is inconvenient on rough ground. The winginground wig effect aircraft may realize a new airlift paradigm.
The threedimensional model is used to create a simulation of the airplanes takeoff, the simulation shows the ability of the design to achieve its goals. A groundeffect vehicle gev, also called a wingingroundeffect wig, groundeffect craft, wingship or ekranoplan russian. The taper ratio which is the ratio between the tip and the root cords is 0. Effect of wing size on o wing performance students are most likely to conclude that there is an optimum size for the smaller wing, which lies somewhere between. The lippisch configuration was chosen because of its supposed greater inherent stability when moving between in ground effect ige and out of ground effect oge. Rd you can hit the ground at high speed, or at low speed, if your speed component downward is great enough and you dont pull up. Analysis of power ground planes uwa research repository. Considerations for numerical modeling of inverted wings in ground effect article in aiaa journal 4910. The models operation was constrained to ground effect by virtue of its low power. Groundeffect planetrain flies inches above the ground w. Design of a wing section in ground effect iowa state university.
Probably a question of how much of an effect there has to be before people say that its a significant effect. A ground effect vehicle is like a hovercraft, but instead of having a fan blowing air down, air is forced underneath by a slope, wings or other such system. Model ground effect glider improved stability youtube. This was the starting point for my experiments in ground effect some 20 years ago. My first experiments into groundeffect began with a simple lippisch reversedelta model mk1 powered by a model aircraft cox 049 engine figure 2. While the pelican is yet to become a prototype the concept is hardly a new one. At low altitude the main wing gets in groundeffect and is more effective, making a lot of lift. Ground effect vehicle, a vehicle which attains level flight near the surface of the earth due to ground effect. The authors experiments my first experiments into ground effect began with a simple lippisch reversedelta model mk1 powered by a model aircraft cox 049 engine figure 2. Flight done with new trifoil wingplan main wing plus canard plus swallow tail. Ground effect for blended wing body turboprop planes.
The wingtip vortices streaming behind an aircraft follow a downward inclined path for some distance behind the aircraft and then gradually level out to follow a path at a lower level than the aircraft and also drift apart. Flight 77 was not trying to land, nor in a flare, nor at approach speed, thus no high angle of attack, no ground effect, and no cushion. For fixedwing aircraft, ground effect is the increased lift and decreased aerodynamic drag that. Design, development and demonstration of rc airplanes. Pelham phillips langley research center summary some results of a study of the influence of ground induced aerodynamic. In this paper, the study primarily provides the theory of the wings operating in ground effect and involves a flight control model for a prototype wig craft model of the conventional marine. Lift acts perpendicular to the flightpath through the wing s center of lift. An understanding of ground effects is important for the development of many modem aircraft systems and for accurate interpretation of vehicle flying qualities. Compared to ground effect aircraft, they are inefficient. Soviet ge aircraft could fly in oge for clearing obstacles. Data for the tests in the lockheed tunnel were obtained from reference 2.
Part boat, part hovercraft, when travelling at speed this craft generates enough lift from its stub wings to fly 15 to 30 centimeters above the water. Ground effect designs would be similar for travel over flat land or water. Considerations for numerical modeling of inverted wings in. I have a son thats into model planes and i went to a meet with him. If boeings enormous pelican ever flies, it wont be until the end of the decade at the soonest. Ground effect one of the most misunderstood aerodynamic effects is called ground effect. How to make a very simple ground effect vehicle wig paper. For fixed wing aircraft, ground effect is the increased lift and decreased aerodynamic drag that an aircrafts wings generate when they are close to a fixed surface. My intent is to explain it in as simplest terms i can. That is the reason for having a horizontal stabilizer to make the aircraft stable. Experimental investigation of the ground effect of wig craft. Groundeffect planetrain flies inches above the ground w video 12 may 2011, by lisa zyga top the robotic groundeffect vehicle is being tested. Flightmeasured ground effect on a lowaspectratio ogee wing. This gives better pitch stability than the previous tailless canard.
Ground effect s so called air cushion only works for small values of rate of descent. The effect of ice shed into engine induction air inlets, for example when an iceladen airplane flies into air. One convenient way to model an aircraft in ground effect using any potential flow algorithm is to replace the surface of the ground with an image of the aircraft, positioned and oriented as though it were reflected in the surface of the ground. May 12, 2011 by building a robotic ground effect vehicle that flies inches above the ground, researchers from japan may be offering a glimpse into the future of highspeed rail. What is the effect of uneven ground on ground effect vehicles. Ein bodeneffektfahrzeug russisch ekranoplan, englisch ground effect vehicle gev oder winginground wig effect craft. What is the best combination of airfoil shape for flight. When taking off, ground effect may temporarily reduce the stall speed.
And the increased pressure does not come with an induced drag penalty. It is the phenomena when an airfoil is operating close to a boundary such as the ground or water. Flightmeasured ground effect on a lowaspectratio ogee. It occurs when the wing of an aircraft flies in close proximity of the ground approximately one quarter the height of the wing span depending on the aspect ratio of the wing. Fly fast, low and fuel efficient with ground effect treehugger.
Ground effect is a low speed, near the ground, high angle of attack phenomenon. Aerodynamics of flight federal aviation administration. The effect over grass, an uneven surface and sometimes over water is likely to be much less. Ground effect one of the most misunderstood aerodynamic. Due to the ground effect, it is difficult for quadrotor to take off or land precisely. Front view of model mounted inside the wind tunnel. A groundeffect vehicle gev, also called a wingingroundeffect wig, groundeffect craft. By eric mcauley balancing a model airplane is the most important and easiest part of building and flying a model airplane.
Dynamic models have been used for over 50 years by the naca and nasa to predict the spin entry and spin recovery behavior of highly maneuverable military aircraft. While true, remember that gevs wings are much closer to the ground than an aircraft s wing and the goal of the aircraft is different. Undergraduate teams are required to design, build and fly a. There is a mathematical relationship between lift, angle of attack aoa, airspeed, altitude, and the size of the wing. This paper presents a new ground effect model of quadrotor based on the cheesemans model for helicopter. It will never get off the ground, or will be uncontrollable if it does. Ground effects related to landing of airplanes with low. Aircraft may be affected by a number of ground effects, aerodynamic effects due to a flying bodys proximity to the ground one of the most important of these effects is the wing in ground effect, which refers to the reduction in drag experienced by an aircraft as it approaches a height approximately equal to the aircraft s wingspan above ground or other level surface, such as the sea. I have found this to be the most overlooked part of flying your plane. The deltry aircraft in flight remember that its a very slow flyer, much slower and more graceful than most paper airplanes. The model was constructed and was exhibited and demonstrated in an international.
Today in the united states and europe there are several homemade groundeffect planes usually seating no more than four passengers. Ge ground effect oge out of ground effect uncorr uncorrected for changes in angleofattack and stabilator position introduction aerodynamic characteristics of an aircraft may signi. In this paper using a steady twodimensional komega turbulence model, detailed parametric studies have been carried out to examine aerodynamic flow features while aircraft wing flies in close. For some runs this resulted in the air plane flaring to level flight without touching the. Ground effects related to landing of airplanes with lowaspectratiowings by william b. Heavy lifting rc model aerodynamics w b garner, april 20 introduction the society of automotive engineers sae sponsors an rc model airplane competition each year for college undergraduates called the sae design challenge.
A tailheavy aircraft will be more unstable and susceptible to stall at low speed e. Anhdralling also helps trap more air underneath the wings for greater lift. Fly fast, low and fuel efficient with ground effect. The stabilizer generates lift too, making the cg just a little forward from cp, resulting on stable flight.
In cold climate, frozen sea is also fairly level for a herculessized plane just pressure ridges. Wing in ground effect wig not to be confused with ground effect in auto racing explained in this article aircraft may be affected by a number of ground effects, or aerodynamic effects due to a flying bodys proximity to the ground. Ground effect train, an alternative to a magnetic levitation train, using ground effect in aircraft to prevent the vehicle from making contact with the. The wings are significantly shorter than those of comparable aircraft, and this configuration requires a high aftplaced horizontal tail. In the light of the noncataloged failures of aircraft flying in the ground effect region. A typical airto ground propagation scenario with a uav. At low altitude the main wing gets in ground effect and is more effective, making a lot of lift. A helicopter committed to ground effect flight only is an easier way to go, just make it safer. The wig craft model aerodynamic coefficients and centre of pressure were. Pdf the ground proximity may significantly improve the performance of the aircraft, but in some conditions, it affects its.
As you might expect, the impact of ground effect increases the closer to the ground that a wing operates. Jun 08, 20 found that our model ground effect glider had poor pitch stability due to the tail providing positive lift rather than negative lift. The results show that the ground has significant effects on the aerodynamic characteristics of the wig craft model when the wing to ground. Some effects of wing planform and airplane size are shown by use of dynamic cal culations of airplane motions during the landing flare. Ground effect is the name given to the dramatically improved aerodynamic performance of a wing when it operates close to a ground plane. Another model was the lunclass, entering service with the black sea fleet in 1987. So in ground effect, lift is created by pushing air downwards and by increased static pressure underneath the wing, like a hovercraft. Wing in ground effect is quite a new concept of designing fast ships, which. By maintaining constant angle of attack, the glideslope was reduced in ground effect and generally resulted in smooth landings. When an aircraft is on the ground, there is a bending force on the fuselage. Not surprisingly, fixed wing aircraft with low wing fuselage attachment receive maximum ground effect. Dynamic ground effects flight test of an f15 aircraft.
Here i go again talking about my younger days in the 60s on my dads boat. Model ground effect vehicles flight in woolmer industrial estate. How to modify and fly a tethered rubber power model with. At higher altitudes, wing will have less lift, but stabilizer will have the same lift, so cg will be far forward from cp and will make it dive. A model of the f15 ighter is shown mounted on a launching rig attached to a helicopter in preparation for. Wing in ground effect wig is the official term adopted by the united nations international maritime organization imo and the united. Pdf autonomous landing of quadrotor based on ground effect. Generally, the aircraft is stable in roll the dipping wing generates more lift and the aircraft corrects itself. A noseheavy aircraft will be more difficult to takeoff from the ground and to.
There are a number of changes in the flow characteristics around the wing due to this effect. Pdf the aerodynamic characteristics of the winginground effect wig craft model. Liftingline predictions for induced drag and lift in. Power ground planes have been modelled in the literature using numerical techniques such as a transmission line model 27, lumped circuit model 8, 9, the method of moments, 10, finite difference techniques 1115, and the peec method 16, 17. Mar 09, 2010 subarupowered homemade hoverwing is a diy miniekranoplan. Retrospective theses and dissertations iowa state university capstones, theses and dissertations 1994 design of a wing section in ground effect. Incidence will be the same both on wing and stabilizer, with cg around 50% wing chord, like an oldtimer or a clg advice from a friend when i asked he how to make an airplane to get a good speed without looping.
Dont throw it, just release it while your hand is moving forward slowly. Another thing to note is that the maneuverability of the ground effect aircraft is pretty limited if its unable to fly in oge out of ground effect. As indicated in the plot shown below, ground effect typically does not exist when a plane operates more than one wingspan above the surface. I will include videos from several folks and pics also. Ground effects related to landing of airplanes with. Mar 01, 2014 hoverwing type model ground effect vehicle. Mk1 powered by a model aircraft cox 049 engine figure 2. A groundeffect vehicle needs some forward velocity to produce lift dynamically and the principal benefit of operating a wing in ground effect is to reduce its liftdependent drag. Experimental investigation of a winginground effect craft ncbi. A plane with a large wingspan can climb higher above ground while still benefiting from ground effect. Structural analysis of the airplane wing is conducted to define the geometry of the wing spars and skin. Approach speeds are typically around 150 knots, about a third of the speed flight 77 was flying at when impact.
It was a wood boat made at the end of the evolution of wood boatsso it was a well made boat mahogany and oak and well designed dave martin. Comparison of the groundplane and image methods for the. The pitching moment increment in ground effect was determined based on the amount of elevator trim required. In many cases designers opt for a flat lower side because a convex lower side may in certain situations lead to suction at the lower side, either hydrodynamic or aerodynamic. Apr 27, 2006 but the range would be greatly reduced to 6,500 nautical miles when not using the ground effect. When the vortices of larger aircraft sink close to the ground within 100 to 200 feet, they tend to move laterally over the ground at a. A survey of airtoground propagation channel modeling for. The principal structural units of a fixed wing aircraft are the fuselage, wings, stabilizers, flight. The russians built a whole range of wig aircraft ranging from eightengine monsters to small pleasure craft. There are two effects inherent to vtol aircraft operating at zero and low speeds ige. Ground effect in fixedwing aircraft ground effect in fixed. How to balance your model aircraft properly bairnsdale.
Als ergebnis einer systematischen modellreihe weg vom einflugeligen. I have taught flight students how to use ground effect to advantage in landing a fixed wing aircraft. The wing ship technology corporation, a south korean company, is trying to revive the wing in ground effect idea. Any number of fast moving jets have slammed into the ground at high speeds, high rd. Pats easytolearn techniques produce great, warweary. Pdf experimental investigation of a winginground effect craft. Pdf a flight control model for a ground effect vehicle. In this paper using a steady twodimensional komega turbulence model, detailed parametric studies have been carried out. A recently developed full wave solver employing a mixed potential integral formulation.
Subarupowered homemade hoverwing is a diy miniekranoplan. Fluent solver setting11 solver option densitybased implicit turbulent model k. Oct 27, 20 my design of helicopter ground effect vehicle is much different to the usual and because i must get others to do work for me that creates the situation that you have skeptics on the projects which will insure that you finish up with a lemon. South koreas armed forces have already agreed to buy some and the firm says it hopes to announce its first commercial sales to an oilandgas firm and a mediterranean ferry company shortly. In many general aviation airplanes this effect produces greater lift and less drag for a given angle of attack.
In cases where only nonlos nlos paths exist, when the elevation angle to the uav is large enough, the ag channel may incur smaller diffraction and shadowing losses than near ground terrestrial links. Ground effect is maximised in calm wind conditions and over a smooth and level hard surface. Cfd computation of the ground effect on airplane with high aspect ration wing fig. When landing, ground effect can give the pilot the feeling that the aircraft is floating. The aquaglide 5 is a fiveseat wing in groundeffect. Aircraft basic construction introduction naval aircraft are built to meet certain specified. An inflight investigation of ground effect on a forwardswept wing. At an altitude of 110 wingspan, however, induced drag is decreased by half. Many of the gev articles focus on increased lift in ground effect, which can give the reader the wrong idea about aircraft operations in the same regime. Design and stress analysis of a general aviation aircraft wing. The aquaglide is a fiveseat wing in ground effect vehicle powered by a gasoline engine. Jan 16, 2008 this is what we call ground effect anyway, ive heard ground effect described as beginning 1 wingspan in altitude, and ive also heard people say that its 12 wingspan in altitude. By finding the values for the weight and wing loading of the airplane, the plan form area of the wing s can be calculated to be 1.1221 31 1433 625 1351 1116 1027 79 826 517 705 1253 1224 1492 501 388 96 102 927 563 1414 827 1042 140 725 731 1158 1005 577 922 414 565 427