In a polymer membrane fuel cell more than half of the chemical energy of hydrogen is converted to heat during generation of electricity. This causes an increase in the cell temperature. The Cooling field design has a significant role in cell cooling. The cell's performance and stability are reduced due to inappropriate heat dissipation. In this paper, the cooling flow and heat transfer in cooli...

The effect of two heat additions, rather than one, in a gas turbine engine is analyzed from the second law of thermodynamics point of view. A regenerative Brayton cycle model is used for this study, and compared with other models of Brayton cycle. All fluid friction losses in the compressor and turbine are quantified by an isentropic efficiency term. The effect of pressure ratio, turbine inlet ...

Constantly rising operating pressure and temperature in turbine drivers push the material capabilities of turbine blades to the limit. The recent development of heterogeneous objects by layered manufacturing offers new potentials for the turbine blades. In heterogeneous turbine blades, multiple materials can be synthesized to provide better properties than any single material. A critical task o...

a numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. the continuity and momentum equations were solved first, assuming the wall reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. the results show that at constant inlet and...

in the present study the effect of curvature ratio and coil pitch for tio2/water nanofluid laminar flow on heat transfer behavior and pressure drop through helical coils with different geometries was investigated experimentally. the tio2/water nanofluids at 0.25% to 2% particle volume concentrations have been prepared by using a two-step method. the experiments were performed for coils with cur...

Power station steam turbine stage flow characteristics show the Corresponding relationship between pressure and flow rate, which is the important research foundation for analysis of steam turbine performance and the further optimization analysis of unit. Based on strict theory analysis, this article obtained two important key characteristic coefficients such as the capacity of flow coefficient ...

The combined cycle gas turbine integrates the Brayton cycle as topping cycle and the steam turbine Rankine cycle as bottoming cycle in order to achieve higher thermal efficiency and proper utilization of energy by minimizing the energy loss to a minimum. In this work, the effect of various operating parameters such as maximum temperature and pressure of Rankine cycle, turbine inlet temperature ...

Dual turbocharger turbine is fed by an unequal out-of-phase mass flow charge almost all the time which have significant effects on its performance parameters and flow phenomena which are not well known. Besides fully understanding the flow behavior in the radial turbine suffers from lack of detailed information about the secondary flows. This article studies the secondary flow structure within ...

A novel liquefied natural gas (LNG) fueled power plant is proposed, which has virtually zero CO2 and other emissions and a high efficiency. The plant operates as a subcritical CO2 Rankine-like cycle. Beside the power generation, the system provides refrigeration in the CO2 subcritical evaporation process, thus it is a cogeneration system with two valued products. By coupling with the LNG evapor...

Accurate numerical simulations depend on the correct prediction of all relevant flow phenomena. For many aeronautical devices such as turbomachinery the behavior of boundary layers, wall-shear-stress and wall heat transfer are significant for the performance. Turbulence and transition influence such flow characteristics. Onset and extent of transition can therefore be of high importance for the...