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--- drawingboard:components:propulsion:lift [2024/06/05 23:58] – created tailkinker
+++ drawingboard:components:propulsion:lift [2024/06/06 01:57] (current) – tailkinker
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 ====== Lift Equipment ======
+By harnessing the power of static lift, you can effectively cancel out the mass of your vehicle, making it lighter and more agile. From innovative solutions like gas bags and lift fans to cutting-edge concepts like contragravity and force repulsion, the possibilities are endless. And don't forget that some air-motive systems like helicopters, tilt-rotors, and ornithopters, already provide a significant boost of lift.
+===== Gas Bags =====
+This might be the worst way to lift an aircraft known to man.  But for many years, it was the //only// way to lift an aircraft known to man.  The one advantage it has is that it is a purely static system, requiring little to no power to lift the aircraft.
+To determine the size of your gas bag, start with the mass of your vehicle, in kilograms.
+^  TR  ^Lifting Gas  ^  Volume (m\[s3])  ^  Cost (\[ce])      ^
+|  -1  |Hot Air      |  Mass \[mu] 3.75  |  Volume \[mu] 0.35  |
+|  -1  |Hydrogen     |  Mass             |  Volume \[mu] 2.5   |
+|  -1  |Helium       |  Mass             |  Volume \[mu] 3.5   |
+Hot air has the advantage of being very cheap, but its lifting power is poor.  Hydrogen and helium are much more effective.  Helium is more expensive, but hydrogen has a minor Hindenberg problem.
+You will quickly notice that even the most efficient options will require absolutely ridiculous volumes.  There is no way---none at all!---you can fit these inside a vehicle.  So where do you put these?
+Above the vehicle.
+To find the size of your gas bag, go to the [[drawingboard:fundamentals:scale|Scale]] table and find the Volume of your gas bag.  If you are using a spherical balloon, multiply the Linear value by 1.25 to find the diameter of your balloon.  If, on the other hand, you are using a zeppelin-shaped gas bag, 0.6 times your Linear value becomes the diameter of the zeppelin, but five times your Linear value becomes its length.
+As to hull points...if your gas bag takes damage, it is destroyed.  If you were using hydrogen as your lifting gas, assume that your vehicle becomes a fireball.
+===== Lift Thrusters =====
+If you point a ducted prop, jet engine, rocket motor or reactionless thruster downwards, instead of backwards, it generates lift.  For every ten Newtons of thrust the engine could generate, it produces one kilogram of static lift.
+If the vehicle remains right next to the ground---an altitude no higher than the vehicle's Linear value, in meters---the static lift of such a system is doubled.  If the vehicle has a ground effect skirt, double that static lift again.
+==== GEV Skirt ====
+A GEV skirt occupies internal space, but that's it!  If you have a GEV skirt on the vehicle, 30% of the volume of your vehicle is dedicated to the GEV skirt.  If you're planning on building a hovercraft, make sure you pick a fairly high Density Quotient.
+==== Vectored Thrust ====
+If a thruster of any sort can have its angle changed between forward and down, you can use it for either thrust or lift.  Building an engine like this increases its mass, volume and cost by 50%.
+===== Contragravity =====
+With sufficiently advanced technology, you can screen your vehicle from gravity, allowing it to float free.
+^  TR  ^  Mass (kg)             ^  Cost (\[ce])           ^  Power (kW)      ^
+|  +3  |  Lift \[di] 1000 + 10  |  Lift \[di] 90 + 2,500  |  Lift \[di] 450  |
+|  +4  |  Lift \[di] 2000 + 5   |  Lift \[di] 450 + 500   |  Lift \[di] 450  |
+Use your vehicle's mass, in //kilograms//, as the Lift value.  If you don't need to counter your entire vehicle weight, you can use a lower value.
+===== Levitation =====
+Technology is not the answer here;  this is straight-up cheating.  It might be magic, or some super-science material, but whatever it is, it's totally passive and simply allows the vehicle to ignore the effects of gravity.
+This material (obviously) has no mass, but will cost \[ce]100 or more (possibly //much// more) times the area of the vehicle.  The vehicle is considered to have static lift equal to its mass.