Arnold van Foreest

Transpiration Cooling Using Liquid Water

At the Space Launcher System Analysis (SART) department of DLR-Cologne, a hypersonic spaceplane for passenger transportation is being investigated. A major challenge is the aerodynamic heating of the vehicle. A possible solution for handling the extreme heatloads will be presented. The solution involves an innovative new way of transpiration cooling, using liquid water. The concept has been tested at the arc heated wind tunnel section of DLR-Cologne. The test campaign will be described and the results will be compared with transpiration cooling using a gas as a coolant.

System Investigations of the SpaceLiner Concept in FAST20XX

DLR’s launcher systems analysis division has proposed a visionary, extremely fast passenger transportation concept reaching the edges of space based on rocket propulsion. The paper describes the recent technical progress achieved in the SpaceLiner configuration. The revolutionary ultrafast transport is now under investigation in the EU-funded study FAST20XX (Future high-Altitude high-Speed Transport 20XX) set off in December 2009. The focus of the paper is on all system aspects of the preliminary design including its flight performance impact on design choices. A major new result is the replacement of the original skipping trajectory by a smooth glide obtained in system optimizations.

Transpiration Cooling Tests of Porous CMC in Hypersonic Flow

During hypersonic flight the temperatures on the vehicle can reach very high values in certain locations. A hypersonic flight vehicle needs to be designed aerodynamically efficient. That results in rather small nose and leading edge radii which drives up thermal loads due to the fact that the loads depend on the curvature radius of these elements. Therefore thermal protections is required for these elements. However, even ceramics reach their use temperature limits when e.g. the leading edge radius of a space plane is in the order of only a few centimeters. Transpiration cooling could be a means to handle the thermal loads in certain critical locations for a hypersonic flight vehicle. This paper describes the loads derived for a conceptual space plane vehicle, the SpaceLiner, and also reports on the initial tests for transpiration cooling of ceramic matrix composites in the hypersonic flow of an arc jet facility.

Technical Maturation of the SpaceLiner Concept

DLR’s launcher systems analysis division is investigating since a couple of years a visionary, extremely fast passenger transportation concept reaching the edges of space based on rocket propulsion. Work is now focusing on the iterative sizing of all major subcomponents in nominal and off-nominal flight conditions. The paper describes the recent technical progress achieved in the SpaceLiner 7 configuration supported by the EU-funded studies FAST20XX (Future high-Altitude high-Speed Transport 20XX) and CHATT (Cryogenic Hypersonic Advanced Tank Technologies). The focus of the paper is on all system aspects of the reference vehicle’s preliminary design including its nominal trajectory and first assessment of its environmental impact.

Cryogenic Sloshing Tests in a Pressurized Cylindrical Reservoir

Coupling between thermodynamic aspects and sloshing propellant is frequently of interest in cryogenic upper stages, especially during the lift-off phase and in missions including multiple restarts. Particularly in the first case, the fluid dynamic condition of the propellant is mainly influenced by various flight maneuvers. In contrast to storable propellant, cryogenic liquid sloshing evokes disturbances of the thermodynamic equilibrium between liquid and vapor. Under some circumstances, this may be critical leading to ullage collapse. The understanding of these phenomena is of major importance concerning the next generation of cryogenic upper stages. In order to investigate the coupled phenomena, benchmark tests are currently being carried out that are focused on sloshing of LN2 in a cylindrical tank. Three different setups are investigated, where the required tank pressure is established by self-pressurization, GN2 pressurization and GHe pressurization.

Modeling of cryogenic sloshing including heat and mass transfer

The paper discusses heat and mass transfer during sloshing of cryogenic liquids. Experiments hav e been executed to investigate this. The experimental results are analyzed and CFD tools are used to create a better understanding of the physical processes involved. A 1D engineering model has been set up with the goal to simulate the heat and transfer during sloshing with only very short CPU time (not more than a few minutes). -1

The Progress on the SpaceLiner Design in the Frame of the FAST 20XX Program

The SpaceLiner concept developed at DLR combines extremely fast transport (90 minutes from Europe to Australia) with the experience of space flight. As such it is different from the spaceflight which focuses exclusively on space tourism but it combines space tourism with for example business travel. The SpaceLiner is designed to carry 50 passengers in suborbital flight. The conceptual technical design presents some challenges which have already been partially investigated at DLR [1,2,3,4]. The SpaceLiner is further developed in the frame of the FAST 20XX project, which starts this year (2009), funded by the EU. The tasks within this program are discussed and the latest progress on the development will be presented in this paper.