A computational fluid dynamics (CFD) analysis of air distribution in a representative railway vehicle equipped with a heating, ventilation, air conditioning (HVAC) system is presented in this paper. Air distribution in the passenger’s compartment is a very important factor to regulate temperature and air velocity in order to achieve thermal comfort. A complete CFD model, including the car’s geometry in detail, the passengers, the luminaires, and other the important features related to the HVAC system (air supply inlets, exhaust outlets, convectors, etc.) are developed to investigate eight different typical scenarios for Northern Europe climate conditions. The results, analyzed and discussed in terms of temperature and velocity fields in different sections of the tram, and also in terms of volumetric parameters representative of the whole tram volume, show an adequate behavior from the passengers’ comfort point of view, especially for summer climate conditions.

This study presents the Computational Fluid Dynamics (CFD) thermal design and experimental tests results for a multi-tubular solar reactor for hydrogen production based on the ferrite thermochemical cycle in a pilot plant in the Plataforma Solar de Almería (PSA). The methodology followed for the solar reactor design is described, as well as the experimental tests carried out during the testing campaign and characterization of the reactor. The CFD model developed for the thermal design of the solar reactor has been validated against the experimental measurements, with a temperature error ranging from 1% to around 10% depending on the location within the reactor. The thermal balance in the reactor (cavity and tubes) has been also solved by the CFD model, showing a 7.9% thermal efficiency of the reactor. CFD results also show the percentage of reacting media inside the tubes which achieve the required temperature for the endothermic reaction process, with 90% of the ferrite pellets inside the tubes above the required temperature of 900 °C. The multi-tubular solar reactor designed with aid of CFD modelling and simulations has been built and operated successfully.

This study presents a comparison of the experimental tests and CFD results for a multi-tubular solar reactor for hydrogen production in a pilot plant in the Plataforma Solar de Almería. This paper describes the methodology used for the solar reactor design and the experimental tests carry out during the testing and characterization campaign of the plant. The CFD model which has been used to design the solar reactor has been validated with an error around 10%. CFD simulations also allow to solve the thermal balance in the reactor (cavity and tubes) and to calculate the percentage of reacting media inside the tubes which achieve the required temperature for the process. The temperature in the thermocouples is around 1200 °C for the experimental data and a 90% of the ferrite inside the tube is above 900 °C. The multi-tubular solar reactor, which has been design with CFD techniques, has been built and operated successfully.