A Study of Boundary-Layer Characteristics of Turbomachine Blade Rows and Their Relation to Over-All Blade Loss

Stewart, Warner L; Whitney, W. J.; Wong, Robert Y.

doi:10.1115/1.3662671

Cited by 27 publications

(17 citation statements)

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“…Based on this concept a flow loss model was first proposed for axial compressor blades [12,13]. A correlation specifically established for axial turbine blades was later presented by Stewart et al [14] as given by Equation (1):…”

Section: Flow Loss Modelmentioning

confidence: 99%

“…This way the proposed methodology supports the loss estimation of axial turbine blade cascades to be achieved simply from the specified upstream and downstream velocity vectors and from some blade geometric parameters, which must be estimated for the specified axial solidity, notably the stagger angle, the mean-line curvature length to chord ratio and the maximum blade thickness-to-chord ratio. [15] to momentum thickness correlation [14] by means of an equivalent diffusion factor based on Equation (3).…”

Section: Cascade Correlationmentioning

confidence: 99%

“…For all the presented cases a fair agreement were found between simulated and experimental results in the subsonic exit Mach number range. Matching of cascade experiments [15] to momentum thickness correlation [14] by means of an equivalent diffusion factor based on Equation (3).…”

Section: Transonic Cascadementioning

confidence: 99%

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Axial Turbine Cascade Correlation

Martins

2016

Applied Sciences

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Abstract:The performance simulation of an axial turbine is achieved in a simple way from the calculation of velocity diagrams. For this purpose, a reliable loss model is needed for the flow through each stationary or rotating axial blade cascade. A loss coefficient assessment is conducted through the establishment of a correlation between the maximum profile velocity ratio and a circulation parameter, dedicated specifically to turbine cascades. A detailed examination of published wind tunnel cascade tests available in the literature provides enough experimental data to support the proposed correlation. Afterwards, the surface diffusion is quantified and the total pressure loss estimation is obtained from the boundary layer momentum thickness and conservation equations for the downstream flow. Further validation of the proposed loss model is presented from published experimental results in turbine cascades and stages. The simulation methodology is also demonstrated in two single-stage steam turbine units applied to the oil refining industry, in comparison with performance factory tests results.

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Section: Flow Loss Modelmentioning

confidence: 99%

Section: Cascade Correlationmentioning

confidence: 99%

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Axial Turbine Cascade Correlation

Martins

2016

Applied Sciences

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“…Vortex strengths for a particular case are found by asymptotic interpolation (equations [16][17][18][19][20] A typical sample case computed by TEM-356A is described below. TYPE = 1.…”

Section: I5)mentioning

confidence: 99%

STOL Transport Thrust Reverser/Vectoring Program, Volume 1

Petit¹,

Scholey²

1973

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“…No presente trabalho é desenvolvido um modelo de estimativa de perdas em grades de palhetas de turbinas axiais a partir dos trabalhos de Stewart [40] e Baljé [45]. O modelo é fundamentado na teoria da camada limite, no conceito do fator de difusão, nas equações de conservação para escoamento compressível e em resultados experimentais obtidos na literatura.…”

Section: Conclusões E Recomendações Para Trabalhos Futurosunclassified

Desempenho De Expansor Axial De Estágio Único E Admissão Parcial Aplicado a Ciclo Rankine Orgânico Para Recuperação De Calor

MARTINS¹

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Martins, Guilherme Leibsohn; Braga, Sergio Leal (Advisor). Performance of Single Stage Partial Admission Axial Expander Applied to a Waste Heat Recovery Rankine Organic Cycle. Rio de Janeiro, 2015. 188p. Doctoral Thesis -Departamento de Engenharia Mecânica, Pontifícia Universidade Católica do Rio de Janeiro.The present work deals with the analysis of the application of a single stage partial admission axial expander in organic Rankine cycle, in order to recover the heat rejected by an internal combustion engine. The selected fluid is R245fa, whose real gas behavior is relevant under the studied conditions, as modeled by the Redlich-Kwong-Soave equation of state. A loss model for the flow through the axial blades is proposed in this work, based on the boundary layer theory, the concept of diffusion factor, wind tunnel cascade tests available in literature and the conservation equations for compressible flow. The diffusion factor is the parameter responsible to quantify the adverse pressure gradient on the blade profile surfaces. The basic geometry and dimensions needed to achieve maximum expander efficiency are determined under several subcritical and supercritical cycle conditions by means of a restrained design optimization algorithm. The optimum value for the evaporator temperature under subcritical cycle is stablished so as to obtain the maximum power from the recovery cycle, according the constructive alternatives considered. The single stage expander design is shown to be greatly influenced by media compressibility and the use of convergentdivergent profiled nozzles is promising to achieve the highest performance potential, especially at high evaporator pressure conditions. Keywordsorganic Rankine cycle; dense gases; axial expander; diffusion factor; profile loss; design optimization. α -ângulo da velocidade absoluta com a direção tangencial; α(T) -função na equação RKS;β -ângulo da velocidade relativa com a direção tangencial; χ − fator de correção; δ -espessura de deslocamento da camada limite;δu -carregamento da palheta (grade);∆ -folga axial entre disco e carcaça;∆ b -folga axial entre palhetas rotativas e estacionárias;∆ s -folga axial entre aro da roda e carcaça;∆ r -folga radial entre topo da palheta e carcaça;∆λ ind -desvio angular induzido na entrada da grade;∆λ dev -deflexão angular na saída da grade; ε -fração de admissão;γ -massa específica;Γ -derivada fundamental da dinâmica do gás;η -eficiência; ϑ -espessura de quantidade de movimento da camada limite;λ -ângulo (grade); ω -fator acêntrico.Ω -velocidade angular.Ω a , Ω b -constantes da equação RKS; ζ -coeficiente de perda referente à energia cinética real. Subscritos:0 -condição de estagnação;1 -estação a montante da grade ou a montante do bocal (estágio);2 -estação a jusante da grade ou entre bocal e rotor (estágio);2te -estação na saída da grade, entre os bordos de fuga;3 -estação a jusante do rotor (estágio);

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A Study of Boundary-Layer Characteristics of Turbomachine Blade Rows and Their Relation to Over-All Blade Loss

Cited by 27 publications

References 0 publications

Axial Turbine Cascade Correlation

Axial Turbine Cascade Correlation

STOL Transport Thrust Reverser/Vectoring Program, Volume 1

Desempenho De Expansor Axial De Estágio Único E Admissão Parcial Aplicado a Ciclo Rankine Orgânico Para Recuperação De Calor

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