Hand-held computer programs for preliminary helicopter design

Abstract

This project gives the user of the HP-4441 handheld programmable calculator a series of programs that give acceptable results during the preliminary phases of the helicopter design process. The project consists of three parts. The first part consists of several short programs and the subroutine form. These programs and subroutines compute density altitude, density, disc area, solidity, tip velocity, induced velocity, coefficient of thrust, tip loss factor, equivalent chord, and ground effect. The second part consists of major subroutines. These subroutines compute profile power, induced power, climb power, parasite power, and total power; equivalent area and induced power for a tandem rotor and data input and change. The third part consists of the main programs. These programs computer the various power requirements for hovering flight, forward (straight and level) flight, vertical flight, and forward climbing flight; also tailrotor power, autorotative flight, and tandem rotor flight.