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1

Rotary Ramjet Engine - Numerical analysis of aerodynamics and combustion

Laube T., Piechna J., Müller N.

Archivum Combustionis

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2014

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Vol. 34 nr 2

129--154

EN

The results of numerical calculations of 2-D and 3-D flows and the combustion process in versions of an advanced rotational engine are presented and analysed. Based on the idea of the ramjet internal flow engine, the project of the rotary engine that generates torque on a shaft was developed and its operation analyzed. In the considered version of the rotary ramjet engine, a set of ramjet engines move around a center axis at high angular velocity to realize the supersonic airflow in their engine inlet. The only mowing part of the engine is a fast rotating disk with obliquely located channels near the external part of the disk forming ramjet engines. The channels in disk perform the functions of compressing the air, combusting the air fuel mixture, and generating thrust with the exhaust gases. The general principle of operation and performance of the rotary engine are discussed. Through the numerical solution of the steady averaged Navier-Stokes equations with k-ɛ turbulence model and non-premixed model of combustion, the basic characteristics of the flow and engine efficiency of the presented designs were predicted. The analysis focuses on the flow, combustion, and thermal challenges. Structural considerations are outside the scope of this paper. Results of the 2-D and 3-D simulations are presented in plots of pressure, fluid velocity, temperature, fuel and oxygen distribution.

2

Numerical investigation of the micro radial disk internal combustion engine

Kurec K., Piechna J., Müller N.

Archivum Combustionis

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2014

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Vol. 34 nr 1

1—26

EN

This work presents a numerical analysis of the flow and combustion phenomena inside the Radial Disk Internal Combustion Engine. In the set of arch chambers forming the engine disk, a mixture of hydrogen peroxide with hydrogen is burned under constant volume conditions. The thermal decomposition of hydrogen peroxide is used as a pilot and stabilizing process of the hydrogen combustion, addressing effectively important challenges for the small dimensions of the channels. The cycle consists of the filling process preceded by the cooling and separation process that is realized by injection of water steam, the combustion, and the expansion process. In the considered numerical model, the cycle is simulated numerically with the commercial software package FLUENT, including the tracking of species and reaction. The inner rotating part of the engine, the disk, is modeled as a moving grid geometry that exchanges flow streams with ports located in the stationary part of the engine, the housing. The implemented model considers problems of sealing, ignition, and quenching. Results of the simulations are presented in form of pressure, temperature, velocity, and species concentration contours as well as torque variation over time.

3

A novel design and preliminary investigation of composite material marine current turbine

Wang J., Piechna J., Müller N.

Archive of Mechanical Engineering

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2011

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Vol. LVIII, nr 4

355-366

EN

A high performance and light-weight wound composite material wheel has been developed and is intended to be used for many purposes. One of these applications is marine current turbine (MCT). Traditionally, major problems influencing the design and operation of MCTs are fatigue, cavitation and corrosion due to the sea water. Considering these factors, implementation of composite materials, especially Kevlar fiber/epoxy matrix, in MCTs is explained in this paper. This novel design pattern of composite material marine current turbine (CMMCT) shows many advantages compared to conventional turbines. This paper investigated several factors which should be considered during this novel turbine design process such as the composite material selection, filament winding of composite wheel and turbine's structural and cavitation analysis. The power coefficient of CMMCT by using CFD is also obtained and the experimental facilities for testing CMMCT in a water towing tank are briefly described.

PL

Wysokiej wydajności wirnik wykonany z materiału będącego tkanym, lekkim kompozytem został opracowany i jest przeznaczony do stosowania do wielu celów. Jedną z tych aplikacji są turbiny wykorzystujące prądy morskie (MCT). Tradycyjnie, główne problemy wpływające na budowę i działanie MCT to problemy zmęczeniowe, związane z kawitacją i korozją w wodzie morskiej. Wyjaśniono w tym artykule dlaczego biorąc pod uwagę powyższe czynniki, wykonano rotor z materiałów kompozytowych, zwłaszcza włókna Kevlar w epoksydowej matrycy. Ten nowy sposób wykonania elementów turbin wykorzystujących prądy morskie z materiałów kompozytowych pokazuje wiele zalet w porównaniu do stosowanych w konwencjonalnych turbinach. W artykule przedstawiono badania kilku czynników, które należy rozważyć w procesie projektowania turbin, takich jak dobór materiałów kompozytowych, sposobu tkania włókien kompozytowych wirnika oraz analizy strukturalnej turbiny i zjawisk kawitacji. Przedstawiono wartość współczynnika mocy turbiny uzyskanego za pomocą CFD oraz przedstawiono krótko podstawowe informacje o stanowisku do badań doświadczalnych turbiny holowanej w basenie.