No abstract

The objective of the work presented in this article was to study the airflow in a vehicle cabin with the typical dimensions and geometry of a multi-purpose vehicle (MPV) with a view to evaluating the thermal comfort through the equivalent temperature index. Tests were carried out on a life-size laboratory model of a car cabin, constructed with a simplified geometry, for different conditions: with and without the presence of a thermal mannequin, with different values of air velocity and temperature and with different regulation of the air inlets. The values of equivalent temperature were determined for each one of the various parts of the body, by two distinct forms: from the measurements performed by the thermal mannequin and from the physical parameters of the airflow, i.e. air velocity and temperature. The mapping of these flow parameters inside the cabin was done through a scanning process carried out with a traversing mechanism with eight low-velocity thermal anemometer probes, controlled from the exterior of the car cabin. Thus, using the values measured in plans in the neighbourhood of the different parts of the thermal mannequin, the equivalent temperature profiles were computed during tests carried out without the presence of the thermal mannequin.

Purpose Indoor environments are characterized by several pollutant sources. Some of these can be sufficiently characterized through the prediction of the airflow and pollutant distribution patterns. The purpose of this study was to simulate, analyze and compare different locations of known pollutant source inside a ventilated room. Design/methodology/approach Computational fluid dynamics modelling approach was used to analyze the prediction of the airflow and pollutant distribution patterns for different locations of known pollutant source inside a ventilated room by mixing ventilation. Findings Distinct areas of poor air quality, perfectly identified by concentration fields, were given. The indoor air quality obtained by the different simulated conditions was analyzed and compared. Research limitations/implications Pollutant concentration was not measured in the validation experiments (qualitative validation based on the velocity fields). Practical implications Once the contaminant concentration fields are calculated based on the source location, the model is very useful to choose the best place to install any pollutant indoor equipment to preserve breathing zones. Originality/value Providing an effective indoor air quality assessment to prevent exposure risk. The results would be useful for making decisions to optimize the design procedure, such as establish the best location to install polluting equipment, occupied areas and their interdependence with ventilation systems. In addition, this tool also helps to choose the best location and correct set point adjustment for the pollutant sensors.

Climate change is expected to influence cooling and heating energy demand of residential buildings and affect overall thermal comfort. Towards this end, the heating (HDD) and cooling (CDD) degree-days along with HDD + CDD were computed from an ensemble of seven high-resolution bias-corrected simulations attained from EURO-CORDEX under two Representative Concentration Pathways (RCP4.5 and RCP8.5). These three indicators were analyzed for 1971–2000 (from E-OBS) and 2011–2040, and 2041–2070, under both RCPs. Results predict a decrease in HDDs most significant under RCP8.5. Conversely, it is projected an increase of CDD values for both scenarios. The decrease in HDDs is projected to be higher than the increase in CDDs hinting to an increase in the energy demand to cool internal environments in Portugal. Statistically significant linear CDD trends were only found for 2041–2070 under RCP4.5. Towards 2070, higher(lower) CDD (HDD and HDD + CDD) anomaly amplitudes are depicted, mainly under RCP8.5. Within the five NUTS II

No abstract

Inadequate air circulation within refrigerated truck chambers is one of the main causes of unsuitable road transport of perishable goods under controlled temperatures. An accurate understanding of indoor air motion is crucial to improving the cold conditions as well as increasing the energy efficiency of mechanical and electrical systems. This paper presents a computational model to predict the velocity, temperature and relative humidity fields in refrigerated truck chambers. The model consists of a computer procedure, in which the general equations describing the airflow pattern and the heat/mass transfer in a refrigerated room are solved using the finite volume method. The computer model was experimentally validated by measurements taken from a reduced-scale model designed to provide similarity with a prototype. The computational model was applied to calculate the cold quality, for example the temperature distribution, provided by different types of air supply systems used in compartments of long-haul vehicles. The results of the numerical solutions demonstrate how the model can be profitably used in practice to study and develop the design of refrigerated chambers.

No abstract

No abstract