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For decades, model rockets have been built using simple recovery methods. These methods do not provide with active control, and are subject to the wind conditions. The aim of this project is to present a technologically challenging alternative. A 2-stage rocket, capable of recovering the first stage by the means of a quadcopter landing system (QLS). This system is formed by four electric motors with propellers and the flight controller. This component is the brain of the rocket, controlling the thrust of each motor in order to provide with active control over the attitude of the vehicle. This flight controller is a commercial one, commonly used for multirrotor aircraft. It must be capable of performing an autonomous landing, without the aid of any external sources. To do so, the INAV configurator has been used, where the return to home (RTH) procedure includes an auto-landing sequence. In addition to, many peripherals have been added to the mount, such as GPS and compass, furthermore, the flight controller board includes a gyroscope, accelerometers and a barometer. With all the avionics assembled, many flight and drop tests have been conducted, in order to validate the performance of the developed system. Additionally, the flight mechanics of the rocket have been studied, in order to understand the physics behind, and the 2-stage rocket has been designed, and simulated. The results obtained by the flight tests conclude that the idea is feasible, and a partial success has been achieved. The prototype was capable of flying, maintaining a stable hover state. However, the autonomous landing resulted in a crash, although it initially worked. Therefore, the idea has room for improvement and further development.

Rocket fuel injectors are in charge of propellant atomization and mixing processes, which determine the performance and stability of the liquid rocket engine itself. This small, yet significant components, are in charge of reducing the size and weight of the propellant droplets while mixing them in the shortest possible amount of time. The injector’s design and implementation must be suitable for performing their tasks in order to achieve maximum performance of the nozzle. Aiming to design and test a feasible rocket injector, a conceptual and physical design is presented, using cheap off-the-shelf stream jet nozzles, and its basic behaviour assessed. The numerical approach involves using computational fluid dynamics software (OpenFOAM) while the experimental approach involves lathe machining considerations. The numerical results indicate that the doublet injector design is feasible and mixture quality can be attained but still needs to be crafted and tested using a particular jet nozzle configuration.

This project details the design of a reusable, small model rocket, which is capable of landing safely over a body of water. Said design includes all the structural components of the rocket and their acquisition, including both commercial components and self-manufactured ones. What makes this rocket stand out among common HPR is the landing system, which consists of a buoyancy device in ated with CO2 during the controlled descent of the rocket. However, this system alone would not guarantee the reusability of the rocket after being launched towards the sea. To ensure the recovery of the rocket, two GPS antennas linked to any conventional smartphone are used. Furthermore, an Arduino-controlled mechanism ensures the tightness of the electronic bay, thus preventing the negative effects water would have on the elements it contains. A structural study is performed to estimate the stresses induced in the rocket during ight and to verify the rocket can comfortably withstand them. Thermal analysis is also conducted to demonstrate that aerodynamic heating is not a threat to the integrity of the rocket. The assembly and refurbishment strategies are presented, to explain how the rocket is expected to be built. Since the construction of the rocket is not part of the project, these strategies will not be checked first-hand. As an alternative, a thorough inspection is made to make sure there are no incompatible actions. Finally, a series of tests of the in atable system were performed. They included the real in ation system and a mock-up of the in atable device. Some conclusions that affected the design of the system were drawn, and the necessary corrective actions were taken

With the “New Space” era we are now seeing a prominent rise in the development of Reusable Launch Vehicles with vertical landing capabilities. This project aims to design and construct a scaled model of such a vehicle but using a cold gas thruster as a means of propulsion. In order to do so, multiple disciplines of engineering are required to develop critical systems such as retro-propulsion, thrust vector control and aerobraking. From structural simulations and CFD analysis to stabilization algorithms and FDM manufacturing, all the methods employed to carry out this complex task presented their complications and challenges, all of which had to be recorded, analysed and overcome. The propellant chosen for the task of propulsion was compressed air, due to its compatibility and availability. Design requirements were established from the beginning but as the project evolved it was clear several of these could not be realized due to limitations of the components available. Most noticeably, the maximum thrust value was found to be restricted by the propulsion system, which makes it impossible to achieve sufficient deceleration for a controlled landing. Having said that, the project successfully lays down the foundations for future iterations and outlines the next steps required in order to solve the main issues related to thrust. If these issues were to be resolved, there is confidence in coming closer to the project’s aim of using compressed air as a means of propulsion

Most traditional simulators used in amateur experimental rocketry make use of basic equations and zero-dimensional models to recreate the performance of solid propellant rocket motors. The usefulness of these simulators is limited, and tend to fail with scale. A new simulator based around idealized and nonidealized phenomena is described in this work, along with the theory used to build it. This simulator considers the motor as a one-dimensional body and discretizes the propellant and chamber along the motor center axis in multiple finite volumes. The new simulator, dubbed PropSim yields results that, although not exactly equal to the real results from a static test, do present and take into account cases and circumstances overlooked by traditional simulators, correcting some of their shortcomings

State of the art rocket engines are reaching performance levels that have become limited by the available manufacturing techniques. With a great focus on these engines’ efficiency, rocket engine producers are focusing on increasing combustion chamber pressures and temperatures, which in turn produces increasingly greater structural and thermal loads. Complex cooling systems are usually used to tackle this issue, being the most predominant formula to use the stored cryogenic propellant as a coolant before being injected in the combustion pressure, more commonly known as regenerative cooling. However, these cooling systems are limited by the state of the art manufacturing techniques. To deal with this issue, efforts have been made to implement modern metal Additive Manufacturing (AM) techniques to rocket engine production. In order to show the extent of the benefits of such innovations, a rocket engine nozzle has been designed following the characteristics of SpaceX’s latest Raptor engines. This design has been tested through Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) simulations so as to validate its performance parameters and study how the implementation of metal AM techniques would improve the engine’s performance. The economic feasibility of such implementation has been studied through the comparison to former techniques, as well as their impact to the environment

This thesis describes a project of design, construction and evaluation of a middle-sized rocket test bench. This project has been developed by the author and the professor without any external funding and with the use of off the shelf components in as many parts as possible. Also, this project has been developed from the inspiration and passion of the teacher and author in this field and for practical use in the future with small and middle-sized model rocket motors.

This thesis has the intention to conduct a study and design of a solid rocket motor and its propellant, for a later implementation, construction and testing of it in a test stand. Thestudy anddesign of the motor will be carried out using as outlines the requirements set either by the legislation or the ones imposed by the objectives of the study. These requirements, together with a bibliographic search for the state of the art and the expressions needed to compute the parameters defining the motor, and the use of adequate software will define the expected performance of the motor.The implementation and construction of the motor itself will be carried out by the thesis’ director, as he has the knowledge on how to operate the machinery to obtain the parts conforming the motor.Finally, the testing of the motor will have to be done by using a test stand, the design and construction of which arethe final master’s thesis of another student. During the test of the motor, the thrust and other parameters will be measured and compared with the calculated onesduring the design phase.