In this paper we construct unstable shocks in the context of 2D isentropic compressible Euler azimuthal symmetry. More specifically, initial data that when viewed self-similar coordinates, converges asymptotically to $$C^{\frac{1}{5}}$$ solution Burgers’ equation. Moreover, show behavior is stable $$C^8$$ modulo a two dimensional linear subspace. Under symmetry assumption, one cannot impose add...

We investigate the properties of r-mode and inertial mode of slowly rotating, non-isentropic, Newtonian stars, by taking account of the effects of the Coriolis force and the centrifugal force. The Coriolis force is the dominant restoring force for both r-mode and inertial mode, which are also called rotational mode in this paper. For the velocity field produced by the oscillation modes the r-mo...

An experimental and analytical study on the performance of carbon dioxide heat pumps for water heating was conducted. The performance of compact, microchannel, water-coupled gas coolers, evaporator, and suction line heat exchanger (SLHX) were evaluated in an experimental facility. Analytical heat exchanger models accounting for the flow orientation and changing CO2 thermophysical properties wer...

In this paper, we study the steady solutions of Euler-Poisson equations in bounded domains with prescribed angular velocity. This models a rotating Newtonian star consisting of a compressible perfect fluid with given equation of state P = eSργ . When the domain is a ball and the angular velocity is constant, we obtain both existence and non-existence theorems, depending on the adiabatic gas con...

This paper presents an expert system for maintenance of one stage compression refrigerating systems. First a steady state model was developed to estimate significant parameters useful for the diagnosis of the functioning state of the plant. The inputs of the model are data coming from sensors installed on the plant. In our study we concluded the necessity of redunduncies to treat efficiently se...

The current paper examines the application of finite-time thermodynamics in order to compare the performance between air-standard cycles, i.e. Atkinson, Diesel and Otto cycles with constant specific heats of working fluid. The effects of input temperature and compression ratio on the net output work and efficiency of the Atkinson cycle, Diesel cycle and Otto cycle are analyzed. It is assumed th...

A method to determine the economic cost of gas turbine compressor fouling was developed. The method is based on the calculation of the influence of the drop of compressor performances (isentropic efficiency, pressure ratio and air mass flow) on Heat Rate and full load power of the gas turbine. A statistical procedure to quantify the drop of compressor performances with fouling and to obtain amb...

We consider a vector kinetic BGK equation leading to isentropic gas dynamics in the relaxation limit. We prove the existence of a weak solution satisfying a kinetic entropy inequality for any initial data with nite energy. Key-words: isentropic gas dynamics { kinetic BGK model { kinetic entropy Mathematics Subject Classi cation: 35L65, 76N15, 35B35, 82C40 Work partially supported by European TM...

We consider a vector kinetic BGK equation leading to isentropic gas dynamics in the relaxation limit. We prove the existence of a weak solution satisfying a kinetic entropy inequality for any initial data with nite energy. Key-words: isentropic gas dynamics { kinetic BGK model { kinetic entropy Mathematics Subject Classi cation: 35L65, 76N15, 35B35, 82C40 Work partially supported by European TM...

engine performance depends on two main factors of engine speed and ignition time. ignition timing can affect engine life, fuel economy and engine power. in this paper, to study engine performance of peugeot 206 tu3a with comparison ratio of 10.5:1 and displacement of 1361cc in matlab software, a two-zone burned/unburned model with the fuel burning rate described by awiebe function was used for ...