Data-based development of a method for estimating temperature loads on sounding rockets

Kurzfassung

The Mobile Rocket Base (MORABA) of the German Aerospace Center (DLR) has been conducting scientific research missions using sounding rockets and balloons since the 1960s. During various flights of these sounding rockets, different temperatures on rocket structures are measured. Either, by the systems of MORABA itself or by experiments on board the rockets. By using and analysing a large number of the measured temperature data, a method for the preliminary design is developed to assess the thermal loads of future research missions. Until now, thermal loads have only been determined using complex, time-consuming and very specific CFD calculations. Based on the measured data, the following different analyses are carried out: Evaluating and classifying the flight data, normalising the data and determining dimensioning parameters for later model development. The available data sets result from a magnitude of different missions using different vehicle configurations. During these missions, temperatures are measured at different measuring positions, e.g. inside the nosecone, the service module of the payload and others. For comparison reasons, the data is categorised according to flights with the same vehicle configuration and measurement positions. Since the measured data sets do not have uniform time intervals, they are normalised by interpolation to a consistent time scale. Finally, possible variables are considered to determine the input parameters for the subsequent development of a methodology. From these investigations, different models are developed with which thermal loads can be determined by using the statistical approach of the Gaussian normal distribution. These models provide results for internal wall temperatures. Therefore, an analytical approach from a diploma thesis is considered to determine outer skin temperatures based on the generated results. Finally, the possibility of validation and the range of validity of these models is discussed. Additionally, recommendations for future measurements and further procedures are described.