A semi-empirical control-volume approach to ejector modeling for transient performance prediction is presented. This new approach is motivated by the need for a predictive real-time ejector sub-system simulation for STOVL integrated flight and propulsion controls design applications. Emphasis is laced on discussion of the approximate characterization of the suggests transient flow predictions a...

Thehigh surface/volumeratio andmechanical stabilityunder cyclic strainmakespolycrystallineNieMneGa metallic foams attractive for magnetic refrigeration. By means of comparison with a polycrystalline bulk material, we have demonstrated that the porous structure of Ni54.8Mn20.2Ga25.0 open-cells metallic foams (porosity varying between44% and58%) reduces the temperature spanof the phase transition...

Refrigeration is one of the leading uses of electric power in the United States. The term "refrigeration" refers to air-conditioning for homes, businesses, and industry and the operation of refrigerators, freezers, and heat pumps. The technology most often used in refrigeration, the vapor compression cycle, is 100 years old, inefficient, and environmentally unsound. Since the 1980s, the refrige...

This paper presents recent developments and state of the art for transcritical CO2 cycle technology in various refrigeration, air-conditioning and heat pump applications. The focus will be on fundamental process and system design issues, including discussions of properties and characteristics of CO2, cycle fundamentals, methods of high-side pressure control, thermodynamic losses, cycle modifica...

The paper focuses on operation of simple refrigeration cycles and considers the selection of controlled variables for two different cycles. One is conventional sub-critical ammonia refrigeration cycle and the other is a trans-critical CO refrigeration cycle. There is no fundamental difference 2 etween the two cycles in terms of degrees of freedom and operation. However, in practical operation t...

Ejectors are a kind of pump that does not have any moving components. In certain cases, the motor fluid may be liquid, steam, or another gas. The research focuses on using nano adsorption combined with multi ejector to fuel sophisticated power plant, which is equipped three shapes steam boiler generators. simulation was accomplished by implementing it cooperation two programs MATLAB A and B, to...

The exergetic analysis is a tool that has been used successfully in many studies aiming a more rational energy consumption to reduce the cost of processes. With this analysis, it is possible to perform an evaluation of the overall process, locating and quantifying the degradation of exergy. This paper applies exergy approach for analyzing the heat exchanger network design and refrigeration of M...

As an energy-saving technology, the ejector is widely used in heating, aerospace, and chemical industry. The performance closely related to its structure, so structure of needs be optimized. In present study, single-factor optimization first carried out, main structural parameters affecting are screened out. Then, response surface method analyze combined effect multiple ejector, find out optima...