What is Lifting: Definition and 255 Discussions

A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing. Whereas a flying wing seeks to maximize cruise efficiency at subsonic speeds by eliminating non-lifting surfaces, lifting bodies generally minimize the drag and structure of a wing for subsonic, supersonic and hypersonic flight, or spacecraft re-entry. All of these flight regimes pose challenges for proper flight safety.
Lifting bodies were a major area of research in the 1960s and 70s as a means to build a small and lightweight manned spacecraft. The US built a number of lifting body rocket planes to test the concept, as well as several rocket-launched re-entry vehicles that were tested over the Pacific. Interest waned as the US Air Force lost interest in the manned mission, and major development ended during the Space Shuttle design process when it became clear that the highly shaped fuselages made it difficult to fit fuel tankage.
Advanced spaceplane concepts in the 1990s and 2000s did use lifting-body designs. Examples include the HL-20 Personnel Launch System (1990) and the Prometheus spaceplane (2010). The Dream Chaser lifting-body spaceplane, an extension of HL-20 technology, was under development as of 2012 as one of three vehicles to potentially carry US crew to and from the International Space Station. In 2015 the ESA Intermediate eXperimental Vehicle performed the first ever successful reentry of a lifting body spacecraft.

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  1. M

    Strength Testing Welded Steel Tubing and Bolts for a Weight Lifting Bench

    I had a piece of box section steel tubing, 400mm long, 5 x 10cm section, 3mm thick. It has a foot welded to the bottom which stabilises it at the floor (this is in red). It is a weight lifting bench. I needed to shorten the length, so I cut it in two and overlapped a join, then fixed it with 3...
  2. V

    Logic behind the Lifting Water problem

    Homework Statement I am trying to understand the logic behind the water pump that requires a user to take into consideration the volume of water at sub-intervals of depth of a tank. There are two types of problems, one where the volume changes at different depths, and one where it doesn't. In...
  3. O

    How Much Torque is Needed to Lift a 1000 lb Load with a Power Screw?

    Homework Statement A power screw with a pitch of 1 mm is directly coupled to a stepper motor rotating at 60 rpm. If the efficiency of the power screw is 35%, what is the stepper motor torque required to raise a 4450 N (1000 lb) load? Homework Equations P=τ*ω τ=F*r The Attempt at...
  4. Y

    Exploring the Physics of Lifting a Box: Why Is It Work?

    Why is it said that no work is done when I lift a box and walk?
  5. S

    Calculating Force, Work, and Power Values For A Lifting Movement

    Thank you in advance for your help! Consider a lifter performing a bench press. The weight of the bar is 225 lbs. Assume the duration of the entire movement from the lowest point to the highest is 1 sec., and that the bar will move a total of 2 ft. from the lifter's sternum to the height of his...
  6. Math Amateur

    Exact Sequences - Lifting Homomorphisms - D&F Ch 10 - Theorem 28

    I am reading Dummit and Foote, Chapter 10, Section 10.5, Exact Sequences - Projective, Injective and Flat Modules. I need help with a minor step of D&F, Chapter 10, Theorem 28 on liftings of homomorphisms. In the proof of the first part of the theorem (see image below) D&F make the following...
  7. Math Amateur

    MHB Exact Sequences - Lifting Homomorphisms - D&F Ch 10 - Theorem 28

    I am reading Dummit and Foote, Chapter 10, Section 10.5, Exact Sequences - Projective, Injective and Flat Modules. I need help with a minor step of D&F, Chapter 10, Theorem 28 on liftings of homomorphisms. In the proof of the first part of the theorem (see image below) D&F make the following...
  8. Math Amateur

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  9. K

    Comparing Work Done Lifting a Box: Man vs. Woman | Understanding Force and Time

    I need some help understanding work. If a man lifts a box up to a shelf and a woman lifts the same box up to the same shelf in half of the time, who is doing more work? I understand that they're moving it the same distance but isn't the woman using more force because she is getting it to...
  10. C

    Designing a Gearbox for Lifting an Object of 2kg

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  11. V

    Weissinger Vs. Prandtl Lifting line theory

    I am not clear about the difference between Pradtl's lifting line theory and Weissinger's. The latter is applied to swept-back wing but does that involve chord-wise circulation distribution?
  12. A

    Raising a 70' Tower: Calculate Cable Force

    This seems simple but I am having trouble with this. I have 70' self supporting tower that I want to be able to raise and lower with a winch. The tower is hinged at the base. I want to use rectangular steel tubing 7' high with a pulley at the top. See PDF attachment. I need to know the force...
  13. C

    Final lifting weight on a static pulley system?

    Dear Advisor, I tried to read books and searched all around before posting new topic here... I'm carying out testing a hoisting winch at load 400 kN through a system as in picture. My problem is that due to fiber rope i only can measure exactly wire tension by a load cell installed through...
  14. R

    Calculating Member Forces of a Crane Lifting a 125kg Motor

    Homework Statement This crane lifts a 125 kg heavey motor. What is the member forces of BF and BD? Use 10 m/s^2 as accleration of gravity. https://dl.dropboxusercontent.com/u/11241083/problemtruss.png Homework Equations F=ma Sum Fx=0 Sum Fy=0 Sum M=0 The Attempt at a...
  15. A

    Electromagnet lifting capability increasing unexpectedly

    Hello, I have been performing an experiment in which I am observing the lifting capacity of DC electromagnets while changing variables including current, number of turns, and length of the core. It is a fairly basic experiment as all the theoretical values can be obtained using the formula...
  16. H

    Convergence Error in Matlab Code for Fluid Flow Simulation

    Homework Statement My apologies if the error is an obvious one and many thanks in advance for any help given: I am trying to create a Matlab code that simulates Lifting Line Theory in order to provide an estimate of the lift and drag of a 3D wing. My hope is to later use this as part of...
  17. M

    Lifting an object to put it into a container

    I'm trying something similar, it's a mechanism to lift/tilt a cylinder, in order to drop whatever is inside the cylinder into another box. (the substance cannot be pumped) The cylinder is about 250kg heavy, and I'd have to lift it around 1,5m, then tilt it. I'm afraid I can't lift it with...
  18. R

    Need enginering help - lifting 1000 lbs 16 feet

    Need engineering help -- lifting 1000 lbs 16 feet Ladies & Gents, I am trying to engineer a lifting device. I can build the frame and all that but getting the motor and gearbox sized right is my problem. I am not a math wizz. Some algebra in middle school many many years ago . The load...
  19. D

    Questions on calculating material needed for lifting object

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  20. S

    Forces when lifting a weight and punching

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  21. B

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  22. G

    How Do Angles Affect the Forces in Lifting Tongs?

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  23. N

    How can balloons be used to lift a house?

    I have one interesting question :-) How many balloons would be needed for lifting house? Which variables need to know? How can I calculate it for a particular case? (my house :-D) Thanks very much and sorry for my bad English.
  24. P

    Is My Lack of Strength and Endurance Normal After a Break from Lifting Weights?

    So I decided to go back to a gym membership and get back in shape. About 3 years ago when I was still in grad school I benched about 40 lb dumbells and squatted with 55 lb dumbells. I also rowed with 50 lb dumbells, and military pressed 35-40 lb dumbells. I went to the gym today for the first...
  25. Pruddy

    Solving Work Done in Lifting 150ft Cable, 4lb/ft

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  26. K

    Does the mechanical advantage of a pulley change when lifting yourself

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  27. Saitama

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  28. S

    Positioning a Counterweight for Heavy Crane Lifting

    Homework Statement A large tower crane is used to move heavy objects in a construction site. The crane uses a counter weight with a mass of mw = 1w.0 Mg (mega grams), and the top beam of the crane also has a mass of mc = 1x00.0 kg which is evenly distributed along the beam. The length of...
  29. A

    How Accurate is My Calculation of Calories Burned During Weight Lifting?

    Hello to the Forum. I just started doing some very light weight lifting and decided to do a rough calculation of how many calories I might be burning during each of my workouts, however the figure I arrive at seems too high by comparison with the numbers one regularly see bandied about. What...
  30. P

    Looking for an equation related to lifting force of air

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  31. C

    Feynman's reversible lifting machine analogy- help

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  32. C

    Lifting a Box - Work and Power

    Homework Statement A 7-kg box is being lifted by means of a light rope that is threaded through a single, light, frictionless pulley that is attached to the ceiling. If the box is lifted, at constant acceleration, from rest on the floor to a height of 1.5 m above the floor in 0.42 s, what...
  33. M

    MATLAB How Can Lifting Line Theory Be Applied in MATLAB for Aircraft Wing Design?

    Hi guys, I am studying aerospace engineering doing my final year. I am doing my final year project which is called "Development of Aircraft Wing Design Tool using MATLAB". It is basically to create a basic tool which will help a designer to design wings. I am totally confused on how to go...
  34. A

    Analysis of Lifting Hook for Rolled Cans

    Hello All, I am brand new to this forum and have found information on here quite helpful in the past before I decided to join the forum, so hopefully some of you can help me with my current project. Currently I am trying to design and fabricate a lifting hook for rolled steel cans. The...
  35. marcus

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  36. T

    Question about lifting up 90 Kilogram weight

    I am trying to build a helicopter. please help me. I want to know how much RPM and size of blade needed to lift 90KG of weight. I am planning not to use tail rotators, but I have a solution for this.
  37. C

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  38. J

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    Homework Statement A party balloon(of mass 0.0025kg when empty) is filled with helium to a volume of 0.0045m3. it is tied to a small stone of mass 0.015kg by a light string of length 1.5m to prevent it from flying away. a child holds the balloon at ground level and then releases it...
  39. Z

    Work done in lifting an object against gravity

    Dear fellows I have three questions related to the topic “Lifting an object against gravity”. If we lift an object of mass 5kg we need to apply a little more force than its weight to lift it and suppose we apply 50 N force (gravity is exerting 49 N forces on it) for just a second that...
  40. D

    Need help with numerical lifting line method

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  41. K

    Lifting a prism; coefficient of friction

    Homework Statement A prism has a mass of m = 80 g, and you wish to lift it, touching the upper two faces only. If the coecient of friction between the prism’s surface and your skin is  = 0:4, what is the minimum force that must be applied to each face? Homework Equations F=μR...
  42. C

    Lifting a weight up and bringing it down: work done

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  43. Z

    Determine acceleration when lifting a bucket.

    Homework Statement A bucket of water is raised up out of a well with a device of the rope, and pulleys as shown in figure. The bucket is hanging from the the lower hook and the upper hook is attached to a fixed cross bar of the well. If the mass of the bucket and the water together is m, and...
  44. X

    Physics Forces Problem: Helicopter lifting a truck

    Homework Statement A large (15,000-kg) military helicopter lifts a 6000-kg truck straight up out of a danger zone with an acceleration of 4 m/s2. Calculate the tension in the lifting cable. Homework Equations F = ma W = mg The Attempt at a Solution I believe T = 8.3 * 104N...
  45. U

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  46. G

    Two radii pulley lifting a pack

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  47. wzrdstrm

    How do I determine lifting force

    Gentlemen please. I am trying to find out how much a motor can lift through a gear reduction to a drum connected a block and tackle assembly. The motor can develop 16K N-M of torque, through a gear reduction of 7.51, turning a drum having a diameter of 1 meter, using 0.0508 meter rope. there...
  48. J

    Calculating Leverage with Crates on Hydraulic Lifting Beam

    Homework Statement The crates( one create 500 kg) are placed on a hydraulic lifting beam: 1. State the order of lever used here 2. Calculate the effort required to lift the load 3. Calculate mechanical advantage for this system 4. Calculate the velocity ratio for this system. If the...
  49. J

    Solving Calc Homework: Lifting a Chain to the Ceiling

    Homework Statement Alright, so my calc class isn't getting easier and we started doing 'work' problems, and I'm just not getting it. Here's the question: A 10ft long weighs 25l and hangs from a ceiling. Find the work done in lifting the lower end of the chain to the ceiling so that its level...
  50. D

    Energy change and work involved in lifting a ball

    I was thinking about the work-energy theorem today and how it states that: Wnet = ΔEkinetic If this is true, then when a ball is moved upward a distance of d, the net work done is equal to zero because there is no change in kinetic energy. Because: Work = Force x Displacement for...
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