Path: Orbit/StraightLine
% Finds duration, ideal power-limited rocket, straight-line trajectory This is analytic except in the case of a finite, nonzero vF, in which case fzero is used. Power limit is the only constraint; thrust and exhaust velocity can go to zero or infinity. Uses Leitmann's 1961 result that the optimal acceleration profile is linear in time. The optimal can be either: * Constrained fuel and time, maximized distance OR * Constrained distance and time, minimized fuel OR * Constrained fuel and distance, minimized time. The acceleration profile is: a(t) = A*(tF-tau-t) a is acceleration, A is a constant, tau is a constant, t is mission time, tF is the final time. -------------------------------------------------------------------------- Form: [tF,A,tau] = SLPLFindDuration( xF, Pj, vF, mDry, m0 ) -------------------------------------------------------------------------- ------ Inputs ------ xF (1,:) Final distance (km) Pj (1,:) Jet power (eta*P, eta*sigma*mE) (W) vF (1,:) Final velocity (km/s). Rendezvous/insertion: vF = 0. Intercept/flyby: vF = [], unconstrained mDry (1,:) Dry mass: Engine, payload, tanks, structure (kg) m0 (1,:) Initial (wet) mass (kg) ------- Outputs ------- tF (1,:) Final time (s) A (1,:) Acceleration scale parameter, (m/s^3) tau (1,:) Time between turnaround and tF (s) -------------------------------------------------------------------------- Reference: Leitmann, George. "Minimum Transfer Time for a Power-Limited Rocket." Journal of Applied Mechanics 28, no. 2 (June 1, 1961): 171-78. https://doi.org/10.1115/1.3641648. -------------------------------------------------------------------------- See also See also: SLPLTrajectory --------------------------------------------------------------------------
AC: ACData/ACTConstants SC: SCData/sCTConstants Common: CommonData/Constants Common: CommonData/SwooshWatermark Common: CommonData/xSplashSmall Common: Database/Constant Common: General/CellToMat Common: General/DeleteCell Common: General/MatToCell Common: General/Watermark Common: Graphics/DistanceLabel Common: Graphics/NewFig Common: Graphics/Plot2D Common: Graphics/PltStyle Common: Graphics/TimeLabl
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