Admin : /* Parachute Design @ Esero Luxembourg */

2022-11-10T21:43:02Z

Parachute Design @ Esero Luxembourg

Admin : Page créée avec « == Introduction == The CanSat use a parachute to slow it down when getting back to the earth. Otherwise the CanSat would crash! The parachute is also used to maintain the… »

2022-02-20T00:43:11Z

Page créée avec « == Introduction == The CanSat use a parachute to slow it down when getting back to the earth. Otherwise the CanSat would crash! The parachute is also used to maintain the… »

Nouvelle page

== Introduction ==
The CanSat use a parachute to slow it down when getting back to the earth. Otherwise the CanSat would crash!

The parachute is also used to maintain the CanSat in the proper position to properly orientate the antenna! This is essential to receive telemetry data.

The most simple parachutes to create are:
* the "Flat Shape" Parachute
* the "Cross" Parachute

== Parachute opening & tenseness ==
The process of parachute opening and air flow capturing is a violent process. The tenseness on the fabric, wire, hook may be really impressive at the opening.

So you need to select strong fibres and realise strong assemblies.

The ideal materials are those used for human parachute (Nylon Cord, [https://en.wikipedia.org/wiki/Ripstop Ripstop Nylon]).

== Fundamentals parameters ==
The followings parameters are primary values to use when designing the CanSat's parachute.

* '''Mass''' : between 300gr and 350gr.
* '''Velocity''' : between 8 m/s and 11 m/s (about 29 Km/H and 40 Km/H).
* '''Drag Coefficient''' : the [https://en.wikipedia.org/wiki/Drag_coefficient drag coefficient] depends on the parachute shape and the fluid used (''Air'' in this case).

=== Drag Coefficient ===
* Semi Spherical Parachute : 1.5 (narom), 0.77 (in the table below)
* Cross Shape Parachute : 0.8
* Flat, Hexagone Parachute : 0.8

[[Fichier:ENG-CANSAT-PARACHUTE-20.png]] Source: [https://www.launchwithus.org/lwu-blog/2016/02/17/parachute-size-estimator-for-high-altitude-balloons Parachute Size Estimator]

=== Estimate the Drag Coefficient ===
You can make a drop test from a given height of your CanSat with the parachute.

When terminal velocity is known (measured), you can deduce the ''Drag Coefficient'' from the estimated velocity in free chute (if the CanSat were not equipped with a parachute).

== Flat Circular Parachute ==
[[Fichier:ENG-CANSAT-PARACHUTE-30.png|360px]]

The Flat Parachutes are extremely common in the hobby rocketry fields. Thanks to their simple design, they are cheap and easy to manufacture. They also offers reliable parachute.

The trade-off is the Draft Coefficient (Cd) which is not as high for a given cloth diameter. It is hard to go wrong with a flat circular (or flat hexagonal) parachute.

The typical drag coefficients range goes from 0.75 to 0.80.

You may also find some informations about flat parachute on this [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/flat-parachute-design/ NAROM page].

== Parachute Design @ NAROM ==
The [https://www.narom.no NAROM site in Norway] did publish "The CanSat Book" containing lot of useful information.

The most interesting parts concerns [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/ the Parachute Design].

* [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/parachute-design-calculations/ Parachute Design Calculations]
* [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/descent-physics/ Descent Physics]
* [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/semi-spherical-parachute-design/ Semi-spherical parachute Design]
* [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/cross-parachute-design/ Cross Parachute Design]
* [https://www.narom.no/undervisningsressurser/the-cansat-book/the-primary-mission/parachute-design/flat-parachute-design/ Flat Parachute Design]

== Parachute Design @ Esero Luxembourg ==
The [http://www.cansat.lu Esero Luxembourg] site did publish ressources for cansat contest.

* [https://youtu.be/J-HmIxQ10ec?t=11107 Parachute calculation] ''YouTube'' Excellent introduction with fundamental concept to some advance parachute calculation. A Great ressource.

== Resources ==
* [https://www.nakka-rocketry.net/paracon.html Parachute Design and Construction] by Richard Nakka
* [https://gallery.mailchimp.com/c4ab65df2b61279e33d7ee72b/files/HAB_Parachute_Size_Estimator_v1.0.xlsx Parachute Size Estimator tool] using imperial unit system ([https://www.launchwithus.org/lwu-blog/2016/02/17/parachute-size-estimator-for-high-altitude-balloons Launchwithus.org]) See [https://www.launchwithus.org/lwu-blog/2016/02/17/parachute-size-estimator-for-high-altitude-balloons this article which explains how to use it].
* [https://www.sunward1.com/imagespara/The%20Mathematics%20of%20Parachutes%28Rev2%29.pdf The Mathematics of Parachute] (pdf).

← Version précédente		Version du 10 novembre 2022 à 21:43
Ligne 60 :		Ligne 60 :

	* [https://youtu.be/J-HmIxQ10ec?t=11107 Parachute calculation] ''YouTube'' <br />Excellent introduction with fundamental concept to some advance parachute calculation. A Great ressource.		* [https://youtu.be/J-HmIxQ10ec?t=11107 Parachute calculation] ''YouTube'' <br />Excellent introduction with fundamental concept to some advance parachute calculation. A Great ressource.
		+
		+	== Without Parachute Design @ KSat Germany ==
		+	The [https://www.ksat-stuttgart.de/en/cansat-challenges/fallcani/ KSat Stuttgart] site did publish ressources for ''Fall Can'' concept.

	== Resources ==		== Resources ==

Modèle:COMMON-CANSAT-PARACHUTE - Historique des versions

Admin : /* Parachute Design @ Esero Luxembourg */

Admin : Page créée avec « == Introduction == The CanSat use a parachute to slow it down when getting back to the earth. Otherwise the CanSat would crash! The parachute is also used to maintain the… »