61 research outputs found
Development and Performance of the 10 kN Hybrid Rocket Motor for the Stratos II Sounding Rocket
No full textThis paper presents the development work of the 10 kN hybrid rocket motor DHX-200 Aurora. The DHX-200 Aurora was developed by Delft Aerospace Rocket Engineering (DARE) to power the Stratos II and Stratos II+ sounding rocket, with the later one being launched in October 2015. Stratos II and Stratos II+ are the flagship projects of DARE, a student group working on rocketry at Delft University of Technology. Successors of Stratos II have the eventual goal of reaching space. During the development process two major revisions of the motor have been designed with smaller changes between tests. The second major design revision was made after a first test series showed low combustion efficiency, through the usage of a CFD model to improve mixing. Both revisions have been tested statically in total for 14 times both at facilities of ’Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek’ (TNO) and ’Deutsches Zentrum f ¨ ur Luft- und Raumfahrt’ (DLR). All tests were conducted in a full-scale, flight-ready configuration with the primary goal of demonstrating the required performance for the Stratos II and Stratos II+ sounding rocket. It was found out that the motor suffered from combustion instabilities at around 450 Hz, when operated at its design oxidizer mass flux level of 600 kg=m2=s, that caused low combustion efficiency and elevated heat flux levels in the pre-combustion chamber. Through design changes the instabilities could be lowered and both problems removed. The design goal of total impulse could not be met, but the specific impulse measured was higher than expected. Still, the overall performance proofed to be sufficient enough for the system to be used as the propulsion system for Stratos II+
The stratos rocket: Design, simulation and production of a record breaking rocket
No full textOn March 17, 2009, a rocket named Stratos was launched, by Delft Aerospace Rocket Engineering, or DARE in short. The purpose of this rocket was to break the European altitude record for amateur rockets which was 10.7 km at that time. A design of a small sounding rocket, such as Stratos, is a good example of an interdisciplinary challenge. An optimal design is a combination of structures, manufacturability, propulsion, aerodynamics, electronics and many other aspects The Stratos rocket achieved an apogee altitude of 12.551 meters at the Esrange Space Centre, thereby setting a new European altitude record for amateur rockets. A detailed flight trajectory reconstruction is done, whereby differences between simulation and reality are explained. The objective of this thesis is to give a detailed insight in the design, the simulation tools, the production process and the results of the mission. The design philosophy of the Stratos rocket, simulation software and the production planning concept are valuable tools in the development of newer and more powerful rockets, which could ultimately result in a successor of the Stratos rocket.Space EngineeringAerospace Engineerin
Public private partnerships value in bioenergy projects: Economic feasibility analysis based on two case studies
No full textReal-time Position and Attitude Determination of the Stratos II Sounding Rocket
No full textCurrently, the student amateur rocket association Delft Aerospace Rocket Engineering (DARE), is designing a small sounding rocket to carry payloads to over 50 km, the Stratos II. Proper operation of this rocket will require an on-board position and attitude determination system. In this thesis, it will be researched how this position and attitude determination can be performed. In essence, the research can be divided into three main topics: simulation, measurement and estimation. Flight estimation is the main goal of the research, while simulation and measurements are prerequisites to estimation. A measurement system with low-cost sensors has been designed and built, and during calibration the performance of these sensors has been established. This measurement system has flown in an actual small sounding rocket, the Stratos II concept launcher, and acceleration, angular velocity and atmospheric pressure data have been acquired. Several estimators have been researched, from which the extended Kalman filter was selected as the most suitable to estimate the position and attitude. The accelerometer and gyroscope measurements are used to propagate the state, and the other measurement data to improve the state estimate, and to estimate various noise factors of the sensors. Measurements are generated from simulations of nominal and non-nominal flights, with nominal and non-nominal sensors, to verify the performance of the estimator. It was found that both the flight trajectory, as well as sensor noise factors such as bias and non-orthogonality strongly affect the estimation result. As only coarse requirements on the position and attitude determination system are available, it cannot be concluded with certainty that the developed measurement system and estimator are suitable for the Stratos II. However, preliminary analysis performed in this thesis, indicates that this is the case. Furthermore, in this thesis clear guidelines are established to improve the estimator performance, should the developed system not satisfy the final requirements.Astrodynamics and Space MissionsAerospace Engineerin
Project Stratos; reaching space with a student-built rocket
No full textIn the spring of 2009 a team of 15 TU Delft students travelled to Kiruna, Sweden with only one goal: to launch the rocket Stratos I they had been working on for 2 years to an altitude of over 12km, thereby claiming the European Amateur Rocket Altitude record. These students were part of Delft Aerospace Rocket Engineering (DARE), a Dream Team of the TU Delft involved in research, development, manufacturing and launching of rockets. However, this record-breaking launch was not a single project; it was the first part of a larger endeavour of which the primary goal was to become the first student team in the world to reach space with a student-built rocket.Aerospace Engineerin
T-Minus engineering: A company in rocketry
No full textThe idea started when a group of students from Delft Aerospace Rocket Engineering were sitting at the breakfast table of the Esrange launch base canteen, in the far north of Sweden. It was the day after the successful launch of the self-built Stratos rocket, that broke the European altitude record for amateur rockets. “This is what we love to do, and apparently we are good at it. Let’s try and make a living building rockets”.Aerospace Engineerin
A study of the effect of prior austenite grain size on the microstructure of Quenching and Partitioning steels with Phase-Field Modelling
No full textQuenching and partitioning (Q&P) is a novel processing route that can create microstructures that combine high strength, ductility and easy formability without the excess use of alloying elements by also keeping the production cost low. Therefore, this method is ideal to be applied to steels that are used in the automotive industry. The material is initially annealed at a high temperature to form austenite. Then it is quenched to a temperature below the martensite start temperature to form a controlled fraction of martensite. Second annealing follows, at a lower temperature than the first one, that stabilises the austenitic phase at room temperature. It has been found that the austenite grain size at the end of the first annealing (prior austenite grain size) has a significant impact on the processing method, the final microstructure and consequently on the final properties of the material. In this thesis, phase-field modelling was employed to investigate the role of prior austenite grain size on the quenching and partitioning process. Simulations of the processing were performed for three different prior austenite grain sizes (6, 25 and 67 μm). Microstructures consisting of about 10.5% austenite and 89.5% martensite were created by simulating the first quenching of the Q&P process. Then, the evolution of the microstructure and carbon distribution were investigated for partitioning at 400 ◦C for times up to 4000 s, and quenching to room temperature. The results gave insights into the effect of the prior austenite grain size on the morphology of the microstructure and the kinetics of carbon during partitioning. It was found that a finer microstructure was derived with decreasing PAGS. Moreover, partitioning becomes more efficient because of the shorter distance that carbon has to diffuse, and the even spatial distribution of austenite. Finally, wide grain size distributions of the austenite that is present during partitioning can lead to significant variations in the carbon content among the austenite grains of the final microstructure, especially for short partitioning times. This affects the efficiency of the partitioning process and has an impact on the mechanical stability of the austenite in the final microstructure and consequently on the TRIP phenomenon.Materials Science and Engineerin
Thermo-hydro-mechanical behaviour of compacted MX80 bentonite at 150°C
No full textThis paper presents the behaviour of compacted MX80 bentonite specimens when they are subjected at thermal and thermohydraulic gradients. The purpose of this work is to develop an improved understanding of heat and moisture movement in unsaturated clay barriers at temperatures above 100°C. Each specimen was statically compacted at 1.65 Mg/m3 and has dimensions of 300mm height and 100mm diameter. With the aid of a thermohydraulic column cell it was possible to apply boundary conditions that imitate the conditions in an underground repository. For the two on going tests undertaken in this study the applied temperatures were 25°C and 150°C at the top and bottom of each specimen. For applying the hydraulic gradient, water injected from the top of the specimen at a pressure of 600kPa. The test results show that, the temperature along the depth of the specimen stabilized in about 3-10 days whereas the relative humidity did not equilibrate. The exposure of the specimen at thermohydraulic gradient manifested a greater axial stress than that of the thermal gradient
A Toolbox for Impact Assessment and Sustainability
No full textAbstractImpact Assessment (IA) is increasingly used by the European Commission and Member States to assess the potential economic, social and environmental consequences of new policy initiatives. To support the IA process, the European Network of Excellence LIAISE is developing a Toolbox which is simultaneously accessible and useful for policy makers as well as for the research community. This paper introduces the developed Toolbox, which provides an interactive library of models, publications, projects, good practices, and experts to support IAs. Special emphasis has been given to enable access to adding and editing informatio
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