Path: SCPro/ProTools
% Size an airship to operate with neutral buoyancy on Neptune. A simple mass balance is applied. For neutral buoyancy, the total mass of the vehicle must equal the mass of the atmospheric gas displaced. In this case, the total mass of the vehicle is approximated as: Vehicle Mass = Payload Mass + Hull Fabric Mass + Lifting Gas Mass Assume the lifting gas is Hydrogen. Assume a fixed chemical content of atmosphere, constant at all % altitudes. 80% H, 19% He, 1% Methane. Assume a spherical shape for the balloon to compute volume and surface area as a function of the sphere radius. Type NeptuneAirshipSizing for a demo. ------ Inputs ------ h (1,n) Altitude vector (km). Keep below 1400 km. m0 (1,m) Payload mass vector (kg). ------- Outputs ------- d (.) Data structure with information including: .h (1,n) Altitude vector input .m0 (1,m) Payload mass vector input .massAir (m,n) Mass of air (kg) .massGas (m,n) Mass of lifting gas (kg) .massHull (m,n) Mass of fabric hull (kg) .massVehicle (m,n) Mass of vehicle (kg) .sigmaFabric (1,1) Areal density of fabric .R (m,n) Radius of balloon (m) .S (m,n) Surface area of balloon (m^2) .V (m,n) Volume of balloon (m^3) .rhoA (1,n) Density of air across altitude (kg/m^3) --------------------------------------------------------------------------
Common: Graphics/NewFig SCPro: ProEnvirons/NeptuneDensity
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