Dave Jarvis' Repositories
git clone https://repo.autonoma.ca/repo/autonoma.ca.git
calculators/rocket/payload/Rocket.js
| class Rocket { | ||
| - constructor(wet, payload, diameter, dragCoefficient, specificImpulse) { | ||
| - console.assert(wet >= 1); | ||
| - console.assert(payload >= 1); | ||
| - console.assert(diameter > 0); | ||
| - console.assert(dragCoefficient > 0); | ||
| - console.assert(specificImpulse > 1); | ||
| - | ||
| - this.mass = wet; | ||
| - this.targetMass = wet + payload; | ||
| - this.radius = diameter / 2.0; | ||
| - this.specificImpulse = specificImpulse; | ||
| - this.totalThrust = 0.0; | ||
| - this.targetAltitude = 0.0; | ||
| - this.massFlowRate = 0.0; | ||
| - this.vAcceleration = 0.0; | ||
| - this.hAcceleration = 0.0; | ||
| - | ||
| - const crossSectionArea = Math.PI * this.radius ** 2; | ||
| - this.ballisticCoefficient = dragCoefficient * crossSectionArea; | ||
| - | ||
| - this.flightRecorder = false; | ||
| - this.launched = false; | ||
| - this.relocated = false; | ||
| - this.world = false; | ||
| - } | ||
| + constructor(wetMass, payloadMass) { | ||
| + this.wetMass = wetMass; | ||
| + this.payloadMass = payloadMass; | ||
| + this.dryMass = this.wetMass * 0.1 + this.payloadMass; | ||
| + this.mass = this.wetMass; | ||
| - recorder(flightRecorder) { | ||
| - this.blackBox = flightRecorder; | ||
| - this.flightRecorder = true; | ||
| + this.azimuth = 0.0; | ||
| } | ||
| on(planet) { | ||
| this.planet = planet; | ||
| - this.world = true; | ||
| } | ||
| - translocate(latitude, altitude) { | ||
| - console.assert(!this.launched); | ||
| - console.assert(this.world); | ||
| + fuselage(diameter, dragCoefficient, specificImpulse) { | ||
| + const crossSectionalArea = Math.PI * (diameter / 2) ** 2; | ||
| + this.ballisticCoefficient = dragCoefficient * crossSectionalArea; | ||
| + this.specificImpulse = specificImpulse; | ||
| + } | ||
| + translocate(latitude, altitude) { | ||
| this.latitude = latitude; | ||
| this.altitude = altitude; | ||
| - this.azimuth = 0; | ||
| - | ||
| - const LOCAL_GRAVITY = this.planet.gravity(latitude, altitude); | ||
| - this.vExhaust = this.specificImpulse * LOCAL_GRAVITY; | ||
| - this.maxAcceleration = 5.0 * LOCAL_GRAVITY; | ||
| - this.rotationalSpeed = this.planet.rotationalSpeed(latitude, altitude); | ||
| - this.relocated = true; | ||
| } | ||
| - | ||
| - launch(hVelocity, vVelocity) { | ||
| - console.assert(this.world); | ||
| - console.assert(this.relocated); | ||
| - console.assert(!this.launched); | ||
| - this.launched = true; | ||
| + apogee(targetAltitude) { | ||
| + this.targetAltitude = targetAltitude; | ||
| + } | ||
| - this.hVelocity = hVelocity + this.rotationalSpeed; | ||
| - this.vVelocity = vVelocity; | ||
| + gravity() { | ||
| + return this.planet.gravity(this.latitude, this.altitude); | ||
| + } | ||
| - const dragForce = this.drag(); | ||
| + launch(initialVelocity) { | ||
| + this.exhaustVelocity = this.specificImpulse * this.gravity(); | ||
| + this.maximumAcceleration = 5.0 * this.gravity(); | ||
| + this.vVelocity = initialVelocity * this.planet.soundSpeed(this.altitude); | ||
| - this.massFlowRate = Math.abs(dragForce[1]) / this.vExhaust * 1.001; | ||
| - this.totalThrust = this.vExhaust * this.massFlowRate; | ||
| + this.hVelocity = this.planet.rotationalSpeed(this.latitude, this.altitude); | ||
| + this.hVelocityTarget = this.planet.orbitalSpeed(this.latitude, this.targetAltitude); | ||
| + this.massFlowRate = Math.abs(this.drag()[1]) / this.exhaustVelocity * 1.001; | ||
| } | ||
| - apogee(altitude) { | ||
| - this.hTargetVelocity = this.planet.orbitalSpeed(this.latitude, altitude); | ||
| - this.targetAltitude = altitude; | ||
| + recorder(blackBox) { | ||
| + this.flightRecorder = blackBox; | ||
| } | ||
| drag() { | ||
| - console.assert(this.launched); | ||
| - console.assert(this.relocated); | ||
| - console.assert(this.world); | ||
| - | ||
| const rho = this.planet.airDensity(this.altitude); | ||
| - const hVelocityNet = this.hVelocity - this.rotationalSpeed; | ||
| - const totalSpeed = Math.sqrt(hVelocityNet ** 2 + this.vVelocity ** 2); | ||
| + const vHorNet = this.hVelocity - this.planet.rotationalSpeed(this.latitude, this.altitude); | ||
| + const totalSpeed = Math.sqrt(vHorNet ** 2 + this.vVelocity ** 2); | ||
| const magnitude = 0.5 * rho * this.ballisticCoefficient * totalSpeed ** 2; | ||
| - const forceRatio = [-hVelocityNet / totalSpeed, -this.vVelocity / totalSpeed]; | ||
| + const ratio = [-vHorNet / totalSpeed, -this.vVelocity / totalSpeed]; | ||
| - return [forceRatio[0] * magnitude, forceRatio[1] * magnitude]; | ||
| + return [ratio[0] * magnitude, ratio[1] * magnitude]; | ||
| } | ||
| flying() { | ||
| - console.assert(this.mass > 0); | ||
| - console.assert(this.targetMass > 0); | ||
| - console.assert(this.targetAltitude > 0); | ||
| - | ||
| - return ( | ||
| - this.mass > this.targetMass && | ||
| - this.altitude < this.targetAltitude | ||
| - ); | ||
| + return this.mass > this.dryMass && this.altitude < this.targetAltitude; | ||
| } | ||
| fly(step) { | ||
| - console.assert(this.launched); | ||
| - console.assert(step > 0); | ||
| - | ||
| - const dragForce = this.drag(); | ||
| + const drag = this.drag(); | ||
| - if (this.hVelocity < this.hTargetVelocity) { | ||
| - const magnitude = Math.sqrt( | ||
| - this.hAcceleration ** 2 + this.vAcceleration ** 2 | ||
| - ); | ||
| - const absDragForce = Math.abs(dragForce[1]); | ||
| + if (this.hVelocity < this.hVelocityTarget) { | ||
| + const accMag = Math.sqrt(this.hAcceleration ** 2 + this.vAcceleration ** 2); | ||
| + const absDrag = Math.abs(drag[1]); | ||
| - if (magnitude > this.maxAcceleration && | ||
| - this.vExhaust * this.massFlowRate * 0.98 > absDragForce) { | ||
| + if (accMag > this.maximumAcceleration && this.exhaustVelocity * this.massFlowRate * 0.98 > absDrag) { | ||
| this.massFlowRate *= 0.99; | ||
| } | ||
| - | ||
| - if (this.vExhaust * this.massFlowRate < absDragForce) { | ||
| - this.massFlowRate = absDragForce / this.vExhaust * 1.1; | ||
| + if (this.exhaustVelocity * this.massFlowRate < absDrag) { | ||
| + this.massFlowRate = absDrag / this.exhaustVelocity * 1.1; | ||
| } | ||
| } else { | ||
| this.massFlowRate = 0.0; | ||
| } | ||
| - this.totalThrust = this.vExhaust * this.massFlowRate; | ||
| + this.totalThrust = this.exhaustVelocity * this.massFlowRate; | ||
| const thrusting = this.totalThrust > 0; | ||
| - const vThrust = thrusting ? -dragForce[1] : 0.0; | ||
| - const hThrust = thrusting ? Math.sqrt(this.totalThrust ** 2 - vThrust ** 2) : 0.0; | ||
| + const vThrust = thrusting ? -drag[1] : 0; | ||
| + const hThrust = thrusting ? Math.sqrt(this.totalThrust ** 2 - vThrust ** 2) : 0; | ||
| - this.hAcceleration = dragForce[0] / this.mass + hThrust / this.mass; | ||
| - this.vAcceleration = dragForce[1] / this.mass - this.planet.gravity(this.latitude, this.altitude) + vThrust / this.mass; | ||
| + this.hAcceleration = drag[0] / this.mass + hThrust / this.mass; | ||
| + this.vAcceleration = drag[1] / this.mass + this.gravity() + vThrust / this.mass; | ||
| - this.hVelocity += this.hAcceleration * step; | ||
| this.vVelocity += this.vAcceleration * step; | ||
| + this.hVelocity += this.hAcceleration * step; | ||
| - this.azimuth += this.hVelocity * step + 0.5 * this.hAcceleration * step ** 2; | ||
| this.altitude += this.vVelocity * step + 0.5 * this.vAcceleration * step ** 2; | ||
| + this.azimuth += this.hVelocity * step + 0.5 * this.hAcceleration * step ** 2; | ||
| this.mass -= this.massFlowRate * step; | ||
| - | ||
| } | ||
| - | ||
| - stop() {} | ||
| record(time) { | ||
| - console.assert(this.flightRecorder); | ||
| - | ||
| - this.blackBox.azimuth(time, this.azimuth); | ||
| - this.blackBox.horizontalVelocity(time, this.hVelocity); | ||
| - this.blackBox.horizontalAcceleration(time, this.hAcceleration); | ||
| - this.blackBox.altitude(time, this.altitude); | ||
| - this.blackBox.verticalVelocity(time, this.vVelocity); | ||
| - this.blackBox.verticalAcceleration(time, this.vAcceleration); | ||
| - this.blackBox.thrustAcceleration(time, this.totalThrust / this.mass); | ||
| - this.blackBox.mass(time, this.mass); | ||
| + if (this.flightRecorder) { | ||
| + this.flightRecorder.azimuth(time, this.azimuth); | ||
| + this.flightRecorder.horizontalVelocity(time, this.hVelocity); | ||
| + this.flightRecorder.horizontalAcceleration(time, this.hAcceleration); | ||
| + this.flightRecorder.altitude(time, this.altitude); | ||
| + this.flightRecorder.verticalVelocity(time, this.vVelocity); | ||
| + this.flightRecorder.verticalAcceleration(time, this.vAcceleration); | ||
| + this.flightRecorder.thrustAcceleration(time, this.totalThrust / this.mass); | ||
| + this.flightRecorder.mass(time, this.mass); | ||
| + } | ||
| } | ||
| } |
calculators/rocket/payload/calculator.js
| -/** | ||
| - * The purpose of this code is to help calculate parameters required to | ||
| - * send a rocket into space using a combination of single-stage to orbit | ||
| - * and an electromagnetic accelerator. | ||
| - */ | ||
| - | ||
| import Earth from './Earth.js'; | ||
| -import Rocket from './Rocket.js'; | ||
| import FlightRecorder from './FlightRecorder.js'; | ||
| -import {$} from './Selector.js'; | ||
| +import Rocket from './Rocket.js'; | ||
| document.querySelectorAll('.submit').forEach(button => { | ||
| button.addEventListener('click', function (event) { | ||
| event.preventDefault(); | ||
| - // Inputs | ||
| const INITIAL_VELOCITY = 8.0; // Mach | ||
| const INITIAL_LATITUDE = 1.469167; // degrees | ||
 |
||
| const DRAG_COEFFICIENT = 0.29; | ||
| const SPECIFIC_IMPULSE = 1400.0; // seconds | ||
| - | ||
| - const earth = new Earth(INITIAL_LATITUDE); | ||
| - | ||
| - const SPEED_OF_SOUND = earth.soundSpeed(INITIAL_ALTITUDE); | ||
| - const INITIAL_HORIZONTAL_VELOCITY = 0; | ||
| - const INITIAL_VERTICAL_VELOCITY = INITIAL_VELOCITY * SPEED_OF_SOUND; | ||
| const blackBox = new FlightRecorder(); | ||
| - const rocket = new Rocket( | ||
| - WET_MASS, | ||
| - PAYLOAD_MASS, | ||
| - ROCKET_DIAMETER, | ||
| - DRAG_COEFFICIENT, | ||
| - SPECIFIC_IMPULSE | ||
| - ); | ||
| + const rocket = new Rocket(WET_MASS, PAYLOAD_MASS); | ||
| + const planet = new Earth(INITIAL_LATITUDE); | ||
| - rocket.on(earth); | ||
| + rocket.on(planet); | ||
| rocket.recorder(blackBox); | ||
| + rocket.fuselage(ROCKET_DIAMETER, DRAG_COEFFICIENT, SPECIFIC_IMPULSE); | ||
| rocket.translocate(INITIAL_LATITUDE, INITIAL_ALTITUDE); | ||
| rocket.apogee(TARGET_ALTITUDE); | ||
| - rocket.launch(INITIAL_HORIZONTAL_VELOCITY, INITIAL_VERTICAL_VELOCITY); | ||
| - | ||
| - const DELTA_TIME = 0.01; | ||
| + rocket.launch(INITIAL_VELOCITY); | ||
| let time = 0.0; | ||
| + const TIME_STEP = 0.01; | ||
| - do { | ||
| + while (rocket.flying()) { | ||
| + rocket.fly(TIME_STEP); | ||
| rocket.record(time); | ||
| - rocket.fly(DELTA_TIME); | ||
| - time = parseFloat((time + DELTA_TIME).toFixed(2)); | ||
| + time += TIME_STEP; | ||
| } | ||
| - while (rocket.flying()); | ||
| - rocket.stop(); | ||
| blackBox.plot(); | ||
| }); | ||
Resolves issues with rocket calculations
| Author | djarvis <email> |
|---|---|
| Date | 2024-12-03 22:50:17 GMT-0800 |
| Commit | e89468db95b3909183505f145c2ad549403bb4af |
| Parent | 7e3fb30 |
| Delta | 66 lines added, 134 lines removed, 68-line decrease |