Airbus Sloshing Rocket Workshop 2022
Competition Regulation

1. Introduction

1.1. Background

Modelling the behaviour of sloshing liquids is of significant interest in various fields of the aerospace industry.

In aircraft design, the study of fuel movement in tanks is of paramount importance for the design of the fuel management control system, the evaluation of the handling characteristics of the aircraft and ultimately the assessment of the structural integrity of the containment structure [1].

For modern satellites, the design is often driven towards lightweight structures, high pointing accuracy and long life expectations. These can result in a large proportion of the overall weight being allocated to the liquid propellant. Therefore the movement of the liquid fuel within its containers can significantly affect the dynamics of these systems, during in-orbit controlled manoeuvers and atmospheric gust encounters in the launch phase [1].

1.2    Competition Background

The Airbus Sloshing Rocket Workshop 2022 is an hybrid competition (online and physical) in which teams are required to design a low cost reusable rocket which is destabilized by the movement of water stored in an unpressurised tank located on the rear side of the vehicle.

The rocket design shall incorporate mechanisms to manage the dynamic forces introduced by the sloshing water to maximize its range, time of flight and liquid payload capacity.

The controlling mechanism can be designed based on passive and/or active means and its performance is a key aspect of the design.

This challenge aims to simulate the conditions experienced by real world aerospace vehicles containing liquid propellant such as satellites or next generation aircrafts.

The participants would be provided with a series of lectures focused on the sloshing and designing challenge.

The objective of the competition is to design the vector and the stabilization system. The description and justifications for the design are to be presented in the format of a design report and supported by calculations, simulations and evidence of prototype testing.

The deadline for the reports will be soon published. 

The four best teams from this round would advance to the final round. In this stage, the teams would meet, with modality to be defined, an Airbus team to discuss their design proposals and defend their reports in a 20 minutes presentation format, followed by a Q&A session

2. Technical Requirements

The vector design must conform to the requirements outlined in this document.

2.1    Physical

The vector’s total dimensions shall not exceed the following:

  • Maximum length = 1.5 m;
  • Maximum wingspan = 2.25 m;

The launch angle will be 85 degrees, an offset of 5 degrees from vertical, with a tolerance of +/- 3 degrees.

The primary structure of the vector shall be formed of readily available items forming two or more water tanks:

  • 1 unpressurised tank containing a minimum of 500ml of water. The tank must contain 50% water and 50% air to generate sloshing loads. The fill level at 50% volume must be clearly marked to facilitate easy visualization for the judges.containing a minimum of 500ml of water.
  • 1 or more pressurised tanks containing water for propulsion. 

The total mass of the propellant must be no greater than the mass of the sloshing liquid.

The total weight at take-off shall not exceed 5 kg when filled with liquid.

The judges would stress the importance of approaching the challenge with a flexible and fresh mind, meaning that arrangement of the tanks does not have to conform to a traditional rocket shape. Teams are not only warmly encouraged to consider aircraft concepts benefits and drawbacks, but are also expected to include in their report an in-depth investigative appendix about ideas and researches in other disciplines that aviation should take inspiration from.

2.2    Launch Mechanism

The vector must be launched vertically at a pressure less than 10 atmospheres [or 147 psi].

The rocket design shall incorporate a means of pressurizing the propulsion tanks with air. The design should present how the tanks would be filled.

Only air is permitted as an inflation gas and no propellant other than water is permitted. This forbids the use of propellers, propulsive gas, engines and lighter than air gases such as helium.

The ratio of air-to-water inside the propulsion tank or tanks (not the payload tank) is customizable and should be exploited to optimize the performance of the vehicle.

2.3    Control Mechanism

The design shall incorporate a means of controlling the descent of the vector to counteract the destabilizing motion of the sloshing liquid. Details of how the sloshing liquid behavior has been predicted and justification for the embodied solution shall be provided as part of the design submission. This could be achieved by using passive or active means or a combination of both:

  • Passive Control: e.g., baffles. Any singular baffle inside the tank cannot cover more than 50% of the cross-sectional area of the tank.
  • Active Control:g. control surfaces.


2.4    Materials and Cost Items

The vector design shall not rely on COTS (Commercial off-the-shelf) items costing in excess of €300. A bill of materials and cost breakdown is required as part of the design submission. Cost efficient solutions will be awarded more points.

The total cost of the rocket must not exceed €500.

2.5    Flight Performance

The simulated flight would be marked attending the following equation:

                                                                 Flight Score = (Distance [m] +Time [s]) x Payload [kg]/TOW [kg]

3. Competition Marking

The overall competition winner will be decided based on the overall score punctuation between 0 and 400 with the following details. The primary submission will be a report of maximum 20 pages (without appendix) supported by evidence of any physical testing, which for safety reasons is required to access the second phase of the competition.

Introduction [5%]

  •  Background information on the challenge of sloshing liquid propellants in the aerospace industry.
  •  Overview of the design approach taken.
  • Team organization.

Requirements Capture [5%]

  • Using a table format, define the requirements for the design.
  • Requirements and/or optional inputs shall be clearly identified.

Concept Design [15%]

  • Descriptions of several design concepts including explanations of how each concept is derived from the design requirements. Inspiration from not aerospace related or already implemented systems is encouraged.
  • Justification for concept selection, supported by explanations of how the requirements will be met by the chosen concept.
  • Concept selection may include basic sizing and performance calculations.

Detailed Design [40%]

  • Explanation of how the sloshing behavior has been predicted and how the control mechanism has been designed to tackle the dynamic loads introduced.
  • Finalized vehicle geometry, possibly generated from a 3D CAD model.
  • An accompanying analysis which may include design trade studies and optimizations to maximize mission performance.
  • Simulations that support your design.
  • Detailed description of manufacture including: bill of materials, component manufacture, assembly sequence and a cost breakdown.
  • Explanations of how safety and operability have been considered in the design of the vehicle.

Design V&V [10%]

  • An assessment of the final design against the requirements showing how all the mandatory requirements have been met.
  • A test plan showing the means by which compliance with each requirement has been demonstrated by simulation or prototype testing (with at least one video proving successful flight and/or safe recovery of unsuccessful ones).
  • Post processing data acquisition capabilities and data provision of flight might grant teams bonus points.

Conclusion [5%]

Conclusion summarizing design outcomes, reflecting on initial objectives.

Appendix [10%]

Express your considerations on the sloshing control and management challenge: which are the interesting ideas and researches in other disciplines that aviation should take inspiration from, to develop a sustainable and efficient sloshing control (5 pages maximum).

General Report Quality [10%]

4. Organisation and schedule

Participation will be held in teams between two (2) and six (6) members, and it is reserved to students enrolled in an university in the moment of the application. If a prospective participant wants to take part of the competition but lacks of a team to do so, he/she will be contacted by the organisation and assigned to an existing team (after its approval). A new team might be created by the organisation if more than one solo participants apply for the event. 

The event will consist on two phases:

  • First phase  (between February and June) : in an online format, teams will attend a series of webinars and work on their own projects. A final report will be made and sent by each team in order to evaluate the work done.
  • Second phase (in July) : this will consist on a 5-days event where the four best teams will work, presentially, on their proposals and defend their reports. The venue of the event is yet to be defined.

5. Participation Fee

Teams will be composed of a maximum of 6 members. The participation fee is a personal fee (per person per team) and it is as follows:

  • EUROAVIA members: €25/person.
  • Non-EUROAVIA members: €50/person.

Important remarks:
(1) EUROAVIA International will verify the membership status for every member in every team and reserves the right to issue the extra fee in to each non-EUROAVIA or inactive EUROAVIA member.
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(2) The participation fee allows each participant attending the webinars offered by Airbus and other collaborators. The four finalists teams will be covered all the costs regarding the accomodiation, food and transportation between the accomodation and the venue of the event during the days where the final of the competition will take place. Additional costs such as transportation between to the city and/or extra nights/food will not be covered by the organization of the event.

6. Application

The applications will be processed based on the rule first come, first served, prioritising the representation of various universities.
Once you submit your team application you will receive a confirmation e-mail. This does not mean your place in the competition is secured.
After the applications close and have been processed the selected teams to participate will receive an email confirming their acceptance and further information on the payment of the participation fee.

The applications start on Dec 1st at 12:00UTC in

The application period would be opened until Jan 3rd at 23:59UTC.

The Organisation of the competition might contact the teams and individual applicants asking for some important information and/or confirmation in order to proceed with the application. If no answer is received within 72h after being contacted, their place will be given to the next team/applicant in the list.

7. Bibliography

[1] F. Gambioli und A. G. Malan, “Fuel Load in Large Civil Airplanes” in International Forum on Aeroelasticity and Structural Dynamics, Como – Italy, 2017.