Search Results

The Crew Refrigerator/Freezer Racks (RFR) are being developed and built at Astrium Friedrichshafen under ESA contract. The RFR will provide conditioned storage volume for astronaut food during transport in the MPLM and on board the ISS. To support the design of the RFR a thermal model has been established at Astrium in the early project phase using the ESATAN software which is the ESA standard thermal analysis tool. This model has been extended to allow full operational simulation of the RFR during a typical mission scenario. For demonstrating the capabilities of EcosimPro, a state of the art tool to address Environmental Control and Life Support analysis, the same model is built up with EcosimPro. The results are validated by comparing them to those from the ESATAN simulation.

This paper will present the results from the breadboarding phase conducted for the Crew Refrigerator/Freezer Rack project. The Refrigerator/Freezer Racks are designed to supply the International Space Station crew with fresh and frozen food on-board the station and to transport food from ground to the station in the Multi Purpose Logistic Module (MPLM).

The change in mode status of the Attached Pressurized Module (APM), termed a mode transition, is due to the need of changing the APM configuration triggered by nominal or contingency events, i.e: initial system activation and further de/reactivation, payload activation, crew, ground or station initiated mode changes, etc. Past simulations of the APM Cabin Air Loop, for individual operational modes, have been performed by Dornier. This paper presents the results of the hydraulic and thermal analyses of the APM Cabin Air Loop for mode transition with the new version of the European Space Agency (ESA) supported software EcosimPro. The range of analysis has now been extended to long duration simulation of transitions between modes, which was impractical in the past.

The Columbus Orbital Facility (COLUMBUS) is the main European contribution to the ISS. Its Temperature and Humidity Control (THC) subsystem consists of the Condensing Heat Exchanger and Filter Assembly (CHXFA), the Condensate Water Separator Assembly (CWSA) and the Cabin Temperature Control Unit (CTCU). The paper provides a description of the THC subsystem and its equipment focusing on the humidity removal function which has shown to be the major design challenge. Design solutions have been realised by optimising all equipment of the THC with respect to its system needs. Test results both on equipment and on THC subsystem level are presented demonstrating that the humidity removal performance is adequate to meet the system requirements in the wide operational range of COLUMBUS.

The Environmental Control and Life Support System (ECLSS) for both MPLM and APM is developed by Dornier. One of the main ECLSS functions to be realized is the atmosphere pressure control of the module. It includes the Cabin Depressurisation, the Positive Pressure Relief, and the Negative Pressure Relief. In order to verify the functionality of the atmosphere pressure control system (ACS) analyses of different scenarios have to be performed. The analysis method including the governing equations of the three ACS functions is described. The analyses are performed with a Dornier developed software program that solves the set of equations numerically. The results of the analyses in terms of pressure and temperature transients are presented and discussed with respect to the boundary conditions and the influence of humidity.

The Mini Pressurized Logistic Module (MPLM) of the International Space Station (ISSA) is foreseen for the transport of service equipment, experiment racks and service racks to the station. For the orbital operational phase it needs an Environmental Control and Life Support System (ECLSS) to make it commissionable for the astronauts. Because of its short mission time and the usage as a transport vehicle it has no completely autonomous ECLSS functionality. The Temperature and Humidity Control (THC) is supported by the Space Station via an Inter Module Ventilation Interface (IMV l/F). The MPLM ECLS has the requirement to suck revitalized air through the IMV l/F and mix it up with the recirculated air in order to provide a comfortable atmosphere in the MPLM habitable area. The fulfillment of the hydraulic and thermal requirements is verified by test and analysis. With this paper we provide the hydraulic analysis performed with ECOSIM, an ESA approved software tool.

ECOSIM is a software tool for continuous simulation of systems which makes possible a combined representation of different physical aspects of a system, such as fluid flows, chemical reactions, electrical phenomena, and analogue and digital controls, in a single model. ECOSIM is a true modular simulation tool. The user can easily develop re-usable submodels and libraries of parametric components in the ECOSIM language and by taking advantage of the abstractions provided by the program. It is also possible to call FORTRAN or C subroutines. Mathematical modelling is based on an underlying differential algebraic equation solver, which overcomes the common drawbacks of simulators based on ordinary differential equation solvers. This permits very rich equation sets to be employed in the model which in turn opens the door to multi-disciplinary simulation. These capabilities make ECOSIM a very powerful tool for the simulation of Environmental Control and Life Support Systems (ECLSSs).