The following document presents a summary of the CFD simulations performed by EnginSoft S.p.A. to improve the design of the MTF. The development of the internal layout began during the CE study at DLR Institute of Space System from September 7th to September 18th 2015 and was documented in the Design Report [4]. An iterative approach was applied for all the systems considered, improving the models step by step towards the optimum solution. Several iterations were performed for each sub-system, where the modifications were suggested from the results of a baseline simulation, with considerations regarding the costs and the feasibility of the new configurations. In this process ES worked in close collaboration with DLR and AS. This report is focused on thermal, fluid dynamic and environmental analyses, considering the impact of both internal and external variables on systems design. In particular, attention has been paid to the simulation of the AMS which has a key role in conditioning the FEG atmosphere and ensuring the comfort of the plants. For this reason specific simulations have been performed on the AMS unit and supply ducts (described in chapter 3 and 4), and also on the environmental conditions in the FEG (chapter 5). The influence of environmental conditions on the thermal stability of the MTF has also been taken into account (chapter 6).