Dissertations / Theses on the topic 'Impulse turbine'

A turbine was investigated by various methods of calculating its efficiency. The project was based on an existing impulse turbine, a one-stage turbine set in an organic Rankine cycle with the working fluid being R245fa. Various methods of loss calculation were explored in the search for a method sufficiently accurate to make valid assumptions regarding the turbine performance, while simple enough to be time efficient for use in industrial research and development.  The calculations were primarily made in an isentropic manner, only taking into account losses due to the residual velocity present in the exit flow. Later, an incidence loss was incorporated in the isentropic calculations, resulting in additional losses at off-design conditions. Leaving the isentropic calculations, the work by Tournier, “Axial flow, multi-stage turbine and compressor models” was used. The work presents a method of calculating turbine losses separated into four components: profile, trailing edge, tip clearance and secondary losses. The losses applicable to the case were implemented into the model. Since the flow conditions of the present turbine are extreme, the results were not expected to coincide with the results of Tournier. In order to remedy this problem, the results were compared to results obtained through computational fluid dynamics (CFD) of the turbine. The equations purposed by Tournier were correlated in order to better match the present case. Despite that the equations by Tournier were correlated in order to adjust to the current conditions, the results of the losses calculated through the equations did not obtain results comparable to the ones of the available CFD simulations. More research within the subject is necessary, preferably using other software tools.

The aim of this master‘s thesis is retrofit of a 300 MW tandem compound steam turbinetype K300 - 170 with three casings and reheat of steam. In the first part a heat balance of the cycle is calculated for given nominal parameters. Further the thesis is focused only on the high pressure section of the turbine, for which the flow section is designed based on thermodynamic calculations and appropriate blade profiles are selected. Then the stress control of the blading is done. The thesis is concluded with estimation of power loss due to shaft seals and real power output of the turbine is calculated. This thesis also includes a drawing of axial section of the high pressure section of the turbine.

Topic of this diploma thesis is thermodynamical recalculation of turbine TG3 for different parameters and new design of its blading. Introduction deals with theoretical basics of turbines and their components. Second part explains general reasons for retrofit and then specifically for Heating plant Olomouc, where TG3 is located. Third part includes used calculating methods and formulas. Last part presents results, which were calculated in software MS Excel. A cross section drawing is attachment of this thesis.

This master’s thesis deals with design of a high speed steam turbine with detachable condensation module and integrated gearbox. As a source of energy is used heat waste, which is a result of the diesel engines function. Important options concerning conception of the turbo set are discussed in the master’s thesis. Subsequently, thermodynamic calculations for each module are done. Part of the thesis is also simplified calculation of the integral gearbox. Construction drawings of all modules and of the complete turbo set with electrical generator were created based on thermodynamic calculation.

Ocean energy research has grown in popularity in the past decade and has produced various designs for wave energy extraction. This thesis focuses on the performance analysis of a uni-directional impulse turbine for wave energy conversion. Uni-directional impulse turbines can produce uni-directional rotation in bi-directional flow, which makes it ideal for wave energy extraction as the motion of ocean waves are inherently bi-directional. This impulse turbine is currently in use in four of the world's Oscillating Wave Columns (OWC). Current research to date has documented the performance of the turbine but little research has been completed to understand the flow physics in the turbine channel. An analytical model and computational fluid dynamic simulations are used with reference to experimental results found in the literature to develop accurate models of the turbine performance. To carry out the numerical computations various turbulence models are employed and compared. The comparisons indicate that a low Reynolds number Yang-shih K-Epsilon turbulence model is the most computationally efficient while providing accurate results. Additionally, analyses of the losses in the turbine are isolated and documented. Results indicate that large separation regions occur on the turbine blades which drastically affect the torque created by the turbine, the location of flow separation is documented and compared among various flow regimes. The model and simulations show good agreement with the experimental results and the two proposed solutions enhance the performance of the turbine showing an approximate 10% increase in efficiency based on simulation results.
ID: 030646261; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.A.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 81-82).
M.S.A.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Aerospace Engineering; Thermofluid Aerodynamics Systems Track

There is a description of modernisation steam condensing turbine in this Master´s thesis. Electric output is decreased from 250 MW to 160 MW. This thesis is divided into two parts, there is a calculation of heat balance in first part and a calculation of blading in second part. Detail drawing and heat balance are the most important results of this Master´s thesis.

The theme of this thesis is design of single body condensing steam turbine of 50 MW to saturated steam for new nuclear power plant generation. In the thesis is made design and calculation of balancing scheme. On the basis of the calculation is made blades part of turbine. Furthermore, the thesis solves basic strength and structural calculations. The result is drawing of longitudinal cut of the turbine.

The use of Computational Fluid Dynamics (CFD) has become a well-established approach in the analysis and optimisation of impulse hydro turbines. Recent studies have shown that modern CFD tools combined with faster computing processors can be used to accurately simulate the operation of impulse turbine runners and injectors in timescales suitable for design optimisation studies and which correlate well with experimental results. This work has however focussed mainly on Pelton turbines and the use of CFD in the analysis and optimisation of Turgo turbines is still in its infancy, with no studies showing a complete simulation of a Turgo runner capturing the torque on the inside and outside blade surfaces and producing a reliable extrapolation of the torque and power at a given operating point. Although there have been some studies carried out in the past where injector geometries (similar for both Pelton and Turgo turbines) have been modified to improve their performance, there has been no thorough investigation of the basic injector design parameters and the influence they have on the injector performance. The aim of this research is to use modern CFD tools to develop models which aid the better understanding of Turgo impulse turbine runners and injectors and facilitate the optimisation of existing designs. CFD is used to model and optimise both the injectors and the runner of a modern commercial Turgo impulse turbine and the accuracy of the models are verified by carrying out experimental tests on the original and optimised designs. The original designs together with experience in the operation of these turbines were provided by the industrial sponsors of this research Gilbert Gilkes and Gordon Ltd. The research described in this thesis can be split into five main parts: 1.Development of a numerical model to analyses the flow through the Turgo runner using modern CFD tools combined with a series of assumptions to reduce the computational time while still retaining the accuracy of the model. Using this model to optimise the design of the Turgo runner provided by Gilkes. 2.Development of a similar numerical model for a simplified 2D injector design to facilitate a study of the impact of the basic design parameters on the performance over a range of operating conditions. Applying these optimisations to the existing Gilkes design and taking the numerical analysis further by including the full injector geometry as well as the branch pipe and guide vanes. 3.Manufacture and experimental testing of the original and optimised Turgo runners. 4.Manufacture and experimental testing of the original and optimised injector designs. 5.Verification of the numerical models developed in 1.) and 2.) by comparison with the experimental results. The numerical model developed in 1.) includes several simplifying assumptions in order to reduce the computational time and produce models which could solve in reasonable timescales allowing many design variations to be analysed. As the runner simulations require a transient analysis of complex multi-phase free surface flow with a rotating frame of reference they are already computationally costly and efforts have to be made to reduce this computational cost if the models are to be effective for optimisation purposes. The runner model simplifications were the exclusion of any casing interactions by not modelling the casing and the use of a 2 blade model analysing only a single blade passage in order to reduce the size of the computational domain. Several modelling assumptions were also introduced and attempts are made to quantify the effects of these assumptions through unit tests. For discretisation of the domain two mesh sizes were used, a coarse mesh which slightly under predicts the efficiency but was suitable for comparing designs and a fine mesh which gave mesh independent results. The fine mesh took over 4 times longer to solve rendering it unfeasible for optimisation purposes and it was therefore used only at key points to verify the design changes made using the coarse mesh. The analysis and optimisation of the injectors carried out in 2.) use similar CFD tools as the runner analysis however the geometry (excluding the branch pipe and guide vanes) could be simplified into a 2D axisymmetric case operating at steady state conditions. This drastically reduces the solve time and allows the use of a mesh independent model and the analysis of hundreds of designs and operating conditions. Once the optimisations had been carried out, the design changes were verified by extending the model to analyse the 3D case with a straight pipe upstream of the injector and a 3D full case including the branch pipe and guide vanes. In 3.), following the optimisation of the runner in 1.), a Finite Element Analysis (FEA) of the runner was carried out to ensure the optimised runner had sufficient strength for operation at the highest heads recommended for a runner of this size. The design was strengthened based on the results of the FEA and CFD was carried out in conjunction with these changes to ensure minimal loss in hydraulic efficiency. The manufacturing process was also researched and Design for Manufacture and Assembly (DFMA) was applied to the strengthened design identifying two optimised designs (LE4 and LE1) which will be tested before and after additional dressing of the leading edges. Both optimised runner designs were manufactured and tested at the Laboratory of Hydraulic Machines, National Technical University of Athens (NTUA). Following the injector analysis and optimisations in 2.), the optimised injectors were manufactured for experimental testing using both the Pelton and the Turgo test rig at NTUA in 4.). As the design changes made were not critical to the strength of the injectors there was no need to carry out a FEA. The CFD model verification in Part 5.) looks initially at the full Turgo system in order to compare the absolute difference between the numerical efficiency and the experimental efficiency of the original Turgo runner at the best efficiency point. The mechanical losses of the test rig are estimated to determine the experimental hydraulic efficiency. The numerical hydraulic efficiency is then determined by calculating the losses upstream of the injector, using standard pipe flow equations and combing these with the losses through the injector, as well as the numerical efficiency of the runner by simulating the runner using the ‘real jet’ profile produced by the full injector simulations. The results showed the numerical model to be over-predicting the efficiency by 1.26%. The numerical difference in the performance of the two injectors is then compared to the experimental difference measured during testing. This is done by importing the ‘real jet’ profiles produced by the full 3D injector simulations into the LE1 runner simulation. This allows the difference in total efficiency between the injectors combined with the runner to be compared to the experimental differences which also includes the impact of the jet on the runner performance. The comparison between the injectors is less accurate as more uncertainties are introduced when combining these models and the differences are smaller however the CFD was able to predict the improvements to within 0.4%. Finally, the numerical differences between the runner designs and the experimental differences are compared showing that the runner model is able to predict differences in hydraulic efficiency to within 0.1%. This accuracy is largely down to that fact that many of the systematic experimental and modelling errors are cancelled out when comparing only the runners.
The CFD model verification has shown that although the absolute performance of the Turgo system can be modelled numerically to within a good degree of accuracy, it requires combining injector and runner models as well as estimating additional losses in the pipework which can prove time consuming. However for design comparison and optimisations the CFD models have been shown to be far more accurate suggesting that this is where these numerical models are most useful.

The content of this thesis is the design of a condensing steam turbine with an output of 80 MWe to a waste incinerator with impulse blading. In this work are elaborated proposals and calculations of balancing schemes, which are used in the next part of the work as a foundation for calculation of the blades part of the turbine. The blades part is designed for two operations - for full condensing operation and for full demand operation. The turbine should contain one process offtake and three unregulated offtakes. Besides that, the thesis solves basic strength control. The thesis is finished with a technical drawing of the longitudinal cut of the turbine.

Diploma thesis deals with calculations of a steam turbine with two uncontrolled extraction points according to the assignment, aerodynamics of the last two stages and operating range with respect to ventilation, range of performance and straining of the last blading under the large condensation pressure deviations. For the first three stages the calculation of prismatic action blades is executed. The fourth and the fifth stages are designed with inconstant reaction over the blades length and their calculation is executed with constant circulation method. For these stages, aerofoil design with respect to their aerodynamic qualities is carried out using Bézier curves. During the whole time verification process of aerofoils qualities, their energy losses and isoentropic Mach number distribution is executed in MISES program in cooperation with Doosan Škoda Power.

This diploma thesis focuses on designing impulse stage steam turbine to be used as the feed pump drive. I consecutively carried out thermodynamic calculation, seals and bearings layouts, with the aim to determine the steam mass flow through the turbine. Furthermore, I conducted turbine blade toughness check-ups, determined the rotor critical rotational speed, check-up rotor critical place (bearing pin) for torsion, and created a clutch screws design. The final part of this thesis pursues the other operating states of the turbine. This thesis is amended by a mechanical drawing of the turbine transection.

The thesis is focused on designing of condensing steam turbine with reheating for combustion of biomass. The turbine is developed to be tandem compound-regenerative with five uncontrolled extraction points. Optimization of reheating pressure is made in the turbine's cycle. The turbine outlet is constructed to lead down to the water cooled condenser. Thesis includes the calculation of heat cycle with the draft of flow channel of high pressure and middle-low pressure turbine. Detailed calculation of middle-low pressure turbine, including stress-strength analysis, is performed. The thesis provides an evaluation of flow scheme of 100 % and 75 % of generator’s power output and the drawing of middle-low pressure turbine in longitudinal section.

Diploma thesis named Condensing steam turbine deals with heat scheme balancing computation of condensing steam turbine K55 and her design. This turbine with 5 unregulated take-offs and overpressure blading type, is computed with (c_a/u) method in the middle of blading diameter. Regulation degree is chosen with impulse blading and feet cross section is checked on durability. At the end of the thesis turbine consumption characteristic is derived from the zero output up to the nominal output. Integrated part of this thesis is conceptional design of longitudal turbine section.

Diploma thesis deals with use of combustion chamber to drive the electric bus charging unit. Based on the research and analysis of operation economy, a turboexpander with an air pressure tank is selected to drive the charging unit. A thermodynamic design is created for this variant. Based on this design a unit layout is proposed. Layout drawings are created for the proposed layout.

The generation of electricity from ocean waves using oscillating water column (OWC) wave energy converters is currently uneconomic due to the high capital cost and low efficiencies of such devices. The bidirectional air turbines utilised in OWCS are one of the principal sources of inefficiency and a significant increase in their performance would improve the prospects of commercial scale wave power generation. The ability of computational fluid dynamics (CFD) to predict the performance of both Wells and impulse type bidirectional turbines for use in OWCS was examined by comparison with experimental results taken from the literature. A design process was then undertaken for a datum impulse turbine and a novel high-efficiency impulse turbine arrangement. Numerical performance predictions are presented with a comparison against experimental data from a large-scale oscillating-flow test rig. An automated design and aerodynamic optimisation system was subsequently developed for application to this novel impulse turbine design. The optimiser employs a hybridised genetic algorithm along with Kriging meta¬models to significantly decrease the number of expensive calls to the 3D-CFD code used to evaluate the objective function. Comparisons to a number of state of the art optimisation algorithms from the literature on some mathematical test functions indicated that the optimiser had equivalent or better performance for most problems. A parameter study was carried out to investigate the effect of various turbine in design variables, before undertaking a 14-variable global design optimisation. A 5-variable optimisation exercise was then performed to investigate the effi- ciency gains that could be achieved by using three-dimensional rotor blades. Substantial gains in performance were attained and the predicted levels of efficiency are significantly higher than those previously reported in the literature for other bidirectional impulse turbine designs.

The generation of electricity from ocean waves using oscillating water column (OWC) wave energy converters is currently uneconomic due to the high capital cost and low efficiencies of such devices. The bidirectional air turbines utilised in OWCS are one of the principal sources of inefficiency and a significant increase in their performance would improve the prospects of commercial scale wave power generation. The ability of computational fluid dynamics (CFD) to predict the performance of both Wells and impulse type bidirectional turbines for use in OWCS was examined by comparison with experimental results taken from the literature. A design process was then undertaken for a datum impulse turbine and a novel high-efficiency impulse turbine arrangement. Numerical performance predictions are presented with a comparison against experimental data from a large-scale oscillating-flow test rig. An automated design and aerodynamic optimisation system was subsequently developed for application to this novel impulse turbine design. The optimiser employs a hybridised genetic algorithm along with Kriging meta¬models to significantly decrease the number of expensive calls to the 3D-CFD code used to evaluate the objective function. Comparisons to a number of state of the art optimisation algorithms from the literature on some mathematical test functions indicated that the optimiser had equivalent or better performance for most problems. A parameter study was carried out to investigate the effect of various turbine in design variables, before undertaking a 14-variable global design optimisation. A 5-variable optimisation exercise was then performed to investigate the effi- ciency gains that could be achieved by using three-dimensional rotor blades. Substantial gains in performance were attained and the predicted levels of efficiency are significantly higher than those previously reported in the literature for other bidirectional impulse turbine designs.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 199-202).
Wind energy is one of the more viable sources of renewable energy and offshore wind turbines represent a promising technology for the cost effective harvesting of this abundant source of energy. To capture wind energy offshore, horizontal-axis wind turbines can be installed on offshore platforms and the study of hydrodynamic loads on these offshore platforms becomes a critical issue for the design of offshore wind turbine systems. A versatile and efficient hydrodynamics module was developed to evaluate the linear and nonlinear loads on floating wind turbines using a new fluid-impulse formulation - the Fluid Impulse Theory(FIT). The new formulation allows linear and nonlinear loads on floating bodies to be computed in the time domain, and avoids the computationally intensive evaluation of temporal and spatial gradients of the velocity potential in the Bernoulli equation and the discretization of the nonlinear free surface. The module computes linear and nonlinear loads - including hydrostatic, Froude-Krylov, radiation and diffraction, as well as nonlinear effects known to cause ringing, springing and slow-drift loads - directly in the time domain and a stochastic seastate. The accurate evaluation of nonlinear loads by FIT provides an excellent alternative to existing methods for the safe and cost-effective design of offshore floating wind turbines. The time-domain Green function is used to solve the linear and nonlinear free-surface problems and efficient methods are derived for its computation. The body instantaneous wetted surface is approximated by a panel mesh and the discretization of the free surface is circumvented by using the Green function. The evaluation of the nonlinear loads is based on explicit expressions derived by the fluid-impulse theory, which can be computed efficiently.
by Godine Kok Yan Chan.
Ph. D.

En el presente trabajo de tesis se desarrolla el diseño energético de una turbina de impulso auto-rectificante de 15 W para el laboratorio de energía (LABEN) de la PUCP. Esto se hace en base a recomendaciones y datos experimentales de investigaciones previas, primero seleccionando el tipo de turbina a tratar en el trabajo y posteriormente definiendo la geometría tomando la base teórica sobre este tipo de turbomáquinas. El diseño se basa en teoría bidimensional de turbomáquinas, principalmente la fórmula de Euler, como también en correlaciones experimentales para la estimación de pérdidas a través de la turbina, como las de Soderberg, Ainley y Mathieson, entre otros. Se utiliza una metodología basada en las correlaciones de pérdidas y la teoría básica de turbinas auto-rectificantes para que con la ayuda de un software computacional (específicamente MathCad) se logre predecir el comportamiento de la turbina. Los resultados analíticos de esta metodología son comparados con datos experimentales de otros autores obteniendo resultados satisfactorios. Se realiza un cálculo iterativo para seleccionar el diámetro y obtener simultáneamente la potencia deseada. Este cálculo iterativo se realiza al reemplazar diferentes diámetros y aplicar el modelo de MathCad junto con los datos de la instalación del LABEN que se selecciona para el trabajo. Finalmente, habiendo verificado que la metodología empleada corresponde con la realidad y habiendo definido las dimensiones de la turbina, se procede a realizar el diseño en 3D de esta, como también los cálculos de resistencia para verificar que no falle mecánicamente. Para la turbina del proyecto, se propone la instalación para el LABEN como también los ensayos a realizar, equipos a utilizar y las gráficas a obtener en base a los datos.
Tesis

碩士
國立高雄海洋科技大學
造船及海洋工程研究所
105
The ocean surface area is about 70% of the earth and the wave energy is one of the potential energy in the ocean renewable energy. The aim of this paper is to investigate the performance of an impulse turbine driven by the reciprocating air flow for ocean wave energy. Because the impulse turbine rotates in the same direction with reciprocating flow, it is suitable for wave energy conversion. In order to enhance the effect of energy conversion, a pair of guide vanes is installed nearby the inlet and outlet of impulse turbine. Thus, the airflow smoothly enters the impulse blades and enhances the performance and energy conversion efficiency. In the numerical analysis, the computational fluid dynamics (CFD) software ANSYS Fluent is used to calculate the streamlines, the distributions of pressure and velocity near the turbine. The torque of the impulse turbine decreases with the rotating speed, at a fixed velocity of air flow. The preliminary results depict that the improvement of the performance of the turbine with guide vanes is about 153% and the maximal power coefficient is 0.3, as optimal rotating speed is 104.7rad/s. Furthermore, the optimal blade numbers of the guide vane and the turbine are 26 and 30, respectively. The influences of the diameter of turbine, the interspace between of turbine and guide vanes, and the height of the blade are also analyzed. The results further propose a useful foundation to design and develop the impulse turbine in power generation for ocean wave energy conversion.

The Ph.D. Thesis describes the modelling and the results of an analytical wave-to-wire model of OWC wave energy converters for the investigation of the entire process of energy transformation from sea waves to the electric wire. This approach is particularly suitable during the early design stages to evaluate the energy extractable from sea waves and properly select the location and the main geometric and operating parameters of the system. The model performs a comprehensive simulation of the entire system to estimate the electric energy production for a specific sea state, based on the joint solution of the analytical models of the three main converters, represented by the chamber, turbine, and generator.

Na unidade curricular de máquinas térmicas, foi desenvolvido um projeto de uma turbina a gás com 300 mm de diâmetro exterior e temperatura de limite metalúrgica fixada nos 1300 K (caso A). O objetivo do presente trabalho incidiu na otimização dessa turbina a gás, visando obter a máxima força de impulso possível. Para tal, atuou-se em dois parâmetros: no aumento do caudal mássico e no aumento da taxa de compressão do ciclo termodinâmico. Inicialmente, procurou-se aumentar o caudal mássico admitido pela turbina a gás (caso B), porém, os resultados obtidos foram pouco significativos face ao que se julgava ser possível alcançar. Em seguida, procedeu-se ao aumento da taxa de compressão do fluido de trabalho, até obter o máximo trabalho útil específico (caso C). Como a velocidade do rotor do compressor radial não podia exceder os 450 m/s, foi necessário adicionar um compressor, de modo a fornecer mais trabalho ao fluido e assim atingir a taxa de compressão desejada. Assim sendo, foi adicionado um compressor axial a montante do radial, já que este permite ter uma maior área de entrada e assim admitir um maior caudal mássico (para a velocidade do escoamento de 150 m/s). Com a adição do compressor axial, foi necessário alterar os componentes já existentes e verificar se as tensões centrífugas e de flexão das pás do rotor da turbina, se encontravam dentro do limite recomendado para alcançar uma vida útil de 10 000 horas. Obtiveram-se duas novas soluções (caso B e C), que foram comparadas com a turbina a gás inicial (caso A). Ambas as soluções responderam ao problema, porém, no caso C obteve-se um crescimento na força de impulso mais significativo do que no caso B. Assim sendo, o caso C foi considerado a solução final e a melhor resposta ao problema proposto.

No seguimento de um trabalho desenvolvido no âmbito da unidade curricular Máquinas Térmicas, onde foi projetada uma miniturbina a gás a partir de um diâmetro máximo imposto, será desenvolvida uma análise das proporções geométricas e dos efeitos da alteração das mesmas, de forma a compreender como é possível, através deste tipo de alterações, melhorar a vida útil da miniturbina a gás, procurando sempre manter a força de impulso tão alta quanto possível. Sendo este tipo de turbinas tipicamente aplicadas à propulsão aérea, a miniturbina a gás em questão será um motor turbojato simples, constituída por um compressor radial e uma turbina axial, ambos com um andar. O método de cálculo utilizado, tanto para o projeto da miniturbina a gás, como para o estudo das consequências das alterações na miniturbina a gás está descrito no livro de COHEN, H. et al. Gas Turbine Theory, 4 ed, Addison-Wesley, 1996. Alterando os valores das proporções geométricas, será possível projetar novos modelos derivados do modelo protótipo, que daqui para a frente referidos como “Geometrias”. A comparação de resultados calculados entre as diversas geometrias e o modelo protótipo irá permitir a compreensão do efeito de cada alteração na miniturbina a gás. O estudo realizado divide-se em três partes, primeiro começou-se por uma análise profunda do projeto original desenvolvido ao longo da unidade curricular Máquinas Térmicas, estudando o funcionamento do motor numa gama de temperaturas limite. Após esta análise preliminar estudou-se o efeito, no funcionamento do motor, da variação da velocidade axial na turbina (componente), originando várias geometrias derivadas do modelo protótipo, com diferentes números de Mach e concentrações de tensões nas pás do rotor da turbina, sendo esta uma zona crítica. Por último foi estudada a redução do diâmetro médio da turbina e os efeitos que esta alteração provoca neste tipo de engenho com as proporções em causa, originando mais uma vez diferentes geometrias com tensões e números de Mach variados. Através dos diferentes estudos e da comparação dos resultados calculados para as várias geometrias, foi possível obter uma percepção geral de como cada variável afeta não só a vida útil do motor, mas também a força de impulso produzida e através desta percepção, projetar novas geometrias que permitem o funcionamento da miniturbina a gás com uma temperatura limite elevada e tensões reduzidas.

O presente trabalho tem como objetivo estudar as proporções de uma microturbina a gás de compressor radial e turbina axial de primeiro andar. O estudo tem como base a alteração dos componentes geométricos com vista a otimização global da turbina. Tomando como base um diâmetro exterior da turbina a gás, velocidade de transporte máxima à saída do rotor do compressor e temperatura limite metalúrgica analisou-se diferentes proporções geométricas: diâmetro de entrada do compressor; diâmetro médio das pás da turbina e, por fim, o diâmetro de saída do compressor. Este estudo permitiu identificar as proporções geométricas que proporcionam força de impulso máxima, bem como identificar limites impostos do escoamento dos gases pelo tubo de chama pela câmara de combustão e tensões que as pás do rotor ficam sujeitas.