Résumé: This paper investigates the influence of fire protection systems and insulation materials on the thermal performance of steel columns. An unprotected column and several columns insulated with different fire protection materials were analyzed using the SAFIR® (2022 version) and ABAQUS simulation (2017 Version). Thermal and mechanical properties of steel were defined according to Eurocode (EC3), and fire exposure was simulated following the ISO-834 standard fire. The following two insulation systems were considered: contour encasement and box encasement. Results show that, for identical material properties and thickness, box encasement significantly slows the temperature rise compared to contour encasement. Vegetable-based fire protection materials such as wood fiber, sheep wool, and expanded cork reduced the steel temperature to 400 °C for up to 80 min and extended fire resistance of steel columns 40 to 310 min. These findings demonstrate that such insulation materials can markedly enhance the fire performance and structural integrity of steel columns, offering a sustainable and effective solution to fire protection.

Résumé: This paper presents a comprehensive characterization of the properties of spruce wood (Picea abies), establishing a foundation for a subsequent investigation into the fire resistance of wooden and hybrid wood-aluminum columns. The effects of density and moisture content on mechanical performance was assessed through compression, tensile, and bending tests conducted on specimens under controlled moisture conditions (oven-dried, air-dried, and moisture-conditioned). The results reveal a strong inverse relationship between moisture content and mechanical strength. However, increased moisture content enhances deformation capacity and energy absorption under compressive loading. These findings highlight the critical importance of moisture control in structural design and provide valuable insights for the application of spruce wood in environments subject to variable humidity. The outcome of this research work establishes the essential groundwork for modeling the fire performance of composite aluminum-wood columns.

Résumé: This paper explores the effect of varying the number and configuration of internal cooling channels on the thermal performance of gas turbine blades. The findings demonstrate the significance of this parameter for improving blade cooling efficiency. Actually, such a study is lacking in the currently available literature. Therefore, six internal cooling configurations were designed using Autodesk Inventor employing the real turbojet airfoil RS1S. The high-pressure gas turbine rotor blades were designed with an 11° twist angle in order to predict the actual behavior of the blade cooling under operating conditions. A series of numerical tests were carried out by coupling the CAD software with COMSOL Multiphysics. A conjugate heat transfer and computational fluid dynamics model were performed. Convective heat flux (CHF), temperature, Nusselt number, air velocity, Reynolds number, and friction force were evaluated for each studied case. The findings showed that adding a second cooling channel to the trailing edge improved the convective heat flux by 63%. On the other hand, creating a new cooling channel increased the blade’s thermal inertia, leading to a cooling limitation. It was also observed that hot spots on the blade surface can develop as a result of air thermal saturation due to extended residence time in the blade channels. In fact, the blade average temperature decreased by 8% using five disconnected channels rather than five serpentine channels. The blade temperature and CHF were reduced by 16 and 22%, respectively, as a result of adding a third channel in the blade mid-zone. Overall, this paper highlighted the potential for improving blade internal cooling through the careful optimization of the number and configuration of internal channels.

Résumé: This paper explores the effect of varying the number and configuration of internal cooling channels on the thermal performance of gas turbine blades. The findings demonstrate the significance of this parameter for improving blade cooling efficiency. Actually, such a study is lacking in the currently available literature. Therefore, six internal cooling configurations were designed using Autodesk Inventor employing the real turbojet airfoil RS1S. The high-pressure gas turbine rotor blades were designed with an 11° twist angle in order to predict the actual behavior of the blade cooling under operating conditions. A series of numerical tests were carried out by coupling the CAD software with COMSOL Multiphysics. A conjugate heat transfer and computational fluid dynamics model were performed. Convective heat flux (CHF), temperature, Nusselt number, air velocity, Reynolds number, and friction force were evaluated for each studied case. The findings showed that adding a second cooling channel to the trailing edge improved the convective heat flux by 63%. On the other hand, creating a new cooling channel increased the blade’s thermal inertia, leading to a cooling limitation. It was also observed that hot spots on the blade surface can develop as a result of air thermal saturation due to extended residence time in the blade channels. In fact, the blade average temperature decreased by 8% using five disconnected channels rather than five serpentine channels. The blade temperature and CHF were reduced by 16 and 22%, respectively, as a result of adding a third channel in the blade mid-zone. Overall, this paper highlighted the potential for improving blade internal cooling through the careful optimization of the number and configuration of internal channels.

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