This paper presents a volume of fluid (VOF) method to solve sloshing problem in a rectangular tank. Navier-Stokes equations are solved by using an implicit time scheme finite volume method, an explicit time split scheme, which requires a small time step, is used for the volume fraction equation. In addition, our VOF method is able to preserve not only the volume but also remove the flotsam and jetsam problem.

In the current context of global warming due to CO2 (carbon dioxide) emissions, mainly produced by power plants and road transportation, it is imperative to optimize the operation of thermal engines in general and of gas turbines in particular. This requires accurate knowledge of their performance. In the case of turbomachines, performance is usually estimated by assuming an adiabatic flow. This assumption is inappropriate, however, for small-scale machines such as turbochargers and micro gas turbines. This study presents the influence of heat transfer on their performance. The concept of entropic temperature is developed and a general exergy analysis conducted in order to quantify accurately the available energy dissipation. Both a turbocharger and a gas turbine with internal heat transfer are investigated. Under the adiabatic assumption, the model results are overestimated. New gas turbine maps have therefore been generated and new operating points defined. The trends of the modeling results thus obtained are compared with the performance measured on a micro gas turbine with and without insulation. Fuel consumption is higher with internal heat transfer.

In the current economic and environmental context dominated by the energy crisis and global warming due to the CO2 emissions produced by industry and road transportation, there is an urgent need to optimize the operation of thermal turbomachinery in general and of gas turbines in particular. This requires exact knowledge of their typical performance. The performance of gas turbines is usually calculated by assuming an adiabatic flow, and hence neglecting heat transfer. While this assumption is not accurate for high turbine inlet temperatures (above 800 K), it provides satisfactory results at the operating point of conventional machines because the amount of heat transferred is generally low (less than 0.5% of thermal energy available at the turbine inlet). Internal and external heat transfer are therefore neglected and their influence is not taken into account. However, current heating needs and the decentralized production of electrical energy involve micro Combined Heat and Power (CHP) using micro-gas turbines (20-250 kW). In aeronautics, the need for a power source with a high energy density also contributes to interest in the design of ultra-micro gas turbines. These ultra and micro machines, which operate on the same thermodynamic principles as large gas turbines, cannot be studied with the traditional adiabatic assumption, as has been underlined by many authors such as Ribaud (2004), Moreno (2006) and Verstraete et al. (2007). During operation, heat is transferred from the turbine to the outside, bearing oil, casing and compressor, thus heating the compressor and leading to a drop in turbine performance. Consequently, the performances reported on the maps developed under the adiabatic assumption are no longer accurate.