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Airbus Sloshing Rocket Workshop

Airbus Sloshing Rocket Workshop 2024
Competition Regulations

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 manoeuvres and atmospheric gust encounters in the launch phase [1].

1.2    Competition Background

The Airbus Sloshing Rocket Workshop 2024 is a hybrid competition (online and physical) in which teams are required to design a low-cost reusable rocket which is destabilised by the movement of water stored in an unpressurised tank located.

The rocket design shall incorporate mechanisms to manage the dynamic forces introduced by the sloshing water to maximise 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 stabilisation 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/or evidence of prototype testing.

The deadline for the reports is on the 31st of May 2024 at 12:00 UTC.  

The (up to) 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 60 minute design review.

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. Photographic evidence will be used to check compliance with this rule, and a penalty will be applied if compliance is failed.

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 visualisation for the judges, containing a minimum of 500ml of water.
  • 1 or more pressurised tankscontaining 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 an in-depth investigative analysis in the introduction to the technical report 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 pressurising 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 optimise 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 destabilising motion of the sloshing liquid. Details of how the sloshing liquid behaviour 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.

Materials and Costs

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 vector must not exceed €500, including estimates for materials and consumables used during the design and manufacturing.

2.5    Flight Performance

Flight performance marking will be based on the following parameters:

  • Distance covered horizontally
  • Altitude reached
  • Total flight time
  • Payload mass/TOW

The scoring formula will be provided before the first webinar.

3. Competition Marking

Qualification for the finals will be based on the scoring of the report submission. The overall competition winner will be decided based on the report score, the flight performance, and the panel feedback on the design review performance.

The primary submission will be a report of maximum 9000 words (without appendix), supported by evidence of any analysis or physical testing performed to assess the safety of the rocket – this assessment of safety using analysis or physical testing is required to access the second phase of the competition. The reports are marked based on the criteria below:

Introduction [10%]

  • Literature review of the sloshing subject
    • Background information on the challenge of sloshing liquid propellants in the aerospace industry.
    • Interesting and innovative ideas aviation should take inspiration from.
  • Team organisation.

Methodology [5%]

  • Overview and explanation of the design approach taken.
  • State the assumptions the team made.

Requirements Capture [5%]

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

Concept Design [20%]

  • Descriptions of several design concepts (exploring aspects such as aerodynamic design, flight performance, stability, control, structural integrity and propulsion), 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 [30%]

  • Explanation of how the sloshing behaviour has been predicted and how the control mechanism has been designed to tackle the dynamic loads introduced.
  • General arrangement drawing of the finalised vehicle geometry, possibly generated from a 3D CAD model.
  • An accompanying analysis which may include analytical or numerical analysis, design trade studies and optimizations to maximise mission performance, etc.
  • Details about the launch and propulsion system.
  • Simulations that support your design.
  • Detailed description of manufacture including:
    • Bill of materials
    • Component manufacture
    • Assembly sequence
    • Cost breakdown.
  • Explanations of how safety and operability have been considered in the design of the vehicle, including a safety assessment. A risk assessment matrix template will be provided, which shall be referenced in the report.

Design V&V [20%]

  • An assessment of the final design against the requirements showing how all the mandatory requirements have been met.
  • Validation of techniques used to design the flying vehicle (such as validation of numerical simulations, presenting inputs, numerical setup and validation of results).
  • A plan showing the means by which compliance with each requirement has been demonstrated by simulation and/or prototype testing.
  • Team may optionally consider data acquisition and processing techniques to support their design.
  • Considerations of safe operations (teams may want to use the Risk Assessment template provided).
  • Optionally, videographic evidence can be provided to demonstrate a successful flight and/or safe recovery of unsuccessful flights (if physical tests have been conducted).

Conclusion [5%]

  • Conclusion summarising design outcomes, reflecting on initial objectives.
  • Provide lessons learnt and suggestions for future work.


  • Supplementary material to the report. Note, that the report must be standalone, i.e. the main body of the report must include all necessary information.
  • The material presented in the appendix will not count towards the overall report mark.

General Report Quality [5%]

A well-composed report produced to a professional standard will be awarded with higher marks. Formatting requirements for the report will be published before the first webinar.

4. Organisation and schedule

Participation will be held in teams between two (2) and six (6) members, and it is reserved to undergraduate students enrolled in a university at the moment of the application. The event is open to bachelor’s and master’s degree students pursuing a BSc, MSc, BEng, MEng, or equivalent degree qualifications.
The event will consist on two phases:

  • First phase: 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. This first phase will take place between February and June 2024. The preliminary schedule of the this first phase is as follows:
    • Webinars will take place between mid February and the beginning of April 2024. The specific dates will be communicated to the teams.
    • Reports and additional required documents will be submitted before 31st May 2024.
    • The classified teams will be announced before June 18th 2024
  • Second phase: this will consist of a 7-day event (counting on arrivals and departures) where the four best teams will work, in person, on their proposals and defend their reports. The event will take place in Lisbon, Portugal between the 9th until the 15th of August 2024.

5. Application Procedure

The applications open on January, 8th at 12:00 UTC and will remain open until February, 5th at 12:00 UTC. Only the team leader shall submit the application.

Below you can find the link for the application form:

Teams will be required to submit a short statement explaining their motivation to participate in the competition, as well as their prior experiences and the university support system they intend to utilise. Up to 15 teams will be admitted, based on the statement of motivation, and taking into account the diversity of the universities represented. Once the team application is submitted, the team leader will receive a confirmation email, which does not mean that the place of the team in the competition is secured.

The Organisation of the competition shall contact the teams asking for some missing information and the confirmation of their willingness to continue with the application procedure. If no answer is received within 72 hours after being contacted, their place will be given to the next team in the priority list.

After the applications are processed, the selected teams will receive an email confirming their acceptance and further information on the payment of the participation fee and an Intellectual Property declaration to sign by a representative of the team and a representative of their university. An email will also be sent to the teams on the waiting list informing them about their position in the same.

The accepted teams will have 72 hours to proceed with the payment and send the proof of payment to If no proof* is received before these 72 hours, the place will be given to the next team in the waiting list.  Same rule applies to the Intellectual Property Document. Once the payment is completed, no changes on the team members will be accepted.


* In the case where the payment is to be done by an external organisation (e.g., University sponsoring the team) with a consequent delay, an additional period for this payment may be granted under the condition of signing a declaration of honour and providing a justification of this matter.

6. Participation Fee and Payment

The participation fee is personal (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 to each non-EUROAVIA or inactive EUROAVIA member.

Shall you have any questions, please enquire us at

(2) The participation fee allows each participant attending the webinars offered by Airbus and other collaborators. For the (up to) four (4) finalists teams, all the costs will be covered regarding the accommodation, food and transportation between the accommodation and the venue of the event during the days where the final of the competition will take place. Additional costs such as transportation to the city and/or extra nights/food will not be covered by the organisation of the event.


(3) Payment methods accepted: bank transfer.

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.