The 6-Inlet Single Stage Axial Turbine Concept for Pulse-Turbocharging: A Numerical Investigation

2019 ◽  
Author(s):  
Nicholas Anton ◽  
Per Birkestad
Keyword(s):  
Numerical Investigation ◽  
Single Stage ◽  
Axial Turbine

A Numerical Investigation on the Volute/Diffuser Interaction due to the Axial Distortion at Impeller Exit

2000 ◽  
Author(s):  
Fahua Gu ◽  
Abraham Engeda ◽  
Mike Cave ◽  
Jean-Luc Di Liberti
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Investigation ◽  
Steady Flow ◽  
Centrifugal Compressor ◽  
Vortex Structure ◽  
Flow Model ◽  
Single Stage ◽  
Mass Flows

Abstract A numerical simulation is performed on a single stage centrifugal compressor using the commercially available CFD software, CFX-TASCflow. The steady flow is obtained by circumferentially averaging the exit fluxes of the impeller. Three runs are made at design condition and off-design conditions. The predicted performance is in agreement with experimental data. The flow details inside the stationary components are investigated, resulting in a flow model describing the volute/diffuser interaction at design and off-design conditions. The recirculation and twin vortex structure are found to explain the volute loss increase at lower and higher mass flows, respectively.

Axial Turbine Design for a Twin-Turbine Heavy-Duty Turbocharger Concept

2018 ◽  
Author(s):  
Nicholas Anton ◽  
Magnus Genrup ◽  
Carl Fredriksson ◽  
Per-Inge Larsson ◽  
Anders Christiansen-Erlandsson
Keyword(s):  
Engine Performance ◽  
Operating Conditions ◽  
Single Stage ◽  
Flow Coefficient ◽  
Speed Ratio ◽  
Heavy Duty ◽  
Turbine Stage ◽  
Axial Turbine ◽  
Radial Turbine ◽  
Turbine Design

In the process of evaluating a parallel twin-turbine pulse-turbocharged concept, the results considering the turbine operation clearly pointed towards an axial type of turbine. The radial turbine design first analyzed was seen to suffer from sub-optimum values of flow coefficient, stage loading and blade-speed-ratio. Modifying the radial turbine by both assessing the influence of “trim” and inlet tip diameter all concluded that this type of turbine is limited for the concept. Mainly, the turbine stage was experiencing high values of flow coefficient, requiring a more high flowing type of turbine. Therefore, an axial turbine stage could be feasible as this type of turbine can handle significantly higher flow rates very efficiently. Also, the design spectrum is broader as the shape of the turbine blades is not restricted by a radially fibred geometry as in the radial turbine case. In this paper, a single stage axial turbine design is presented. As most turbocharger concepts for automotive and heavy-duty applications are dominated by radial turbines, the axial turbine is an interesting option to be evaluated for pulse-charged concepts. Values of crank-angle-resolved turbine and flow parameters from engine simulations are used as input to the design and subsequent analysis. The data provides a valuable insight into the fluctuating turbine operating conditions and is a necessity for matching a pulse-turbocharged system. Starting on a 1D-basis, the design process is followed through, resulting in a fully defined 3D-geometry. The 3D-design is evaluated both with respect to FEA and CFD as to confirm high performance and durability. Turbine maps were used as input to the engine simulation in order to assess this design with respect to “on-engine” conditions and to engine performance. The axial design shows clear advantages with regards to turbine parameters, efficiency and tip speed levels compared to a reference radial design. Improvement in turbine efficiency enhanced the engine performance significantly. The study concludes that the proposed single stage axial turbine stage design is viable for a pulse-turbocharged six-cylinder heavy-duty engine. Taking into account both turbine performance and durability aspects, validation in engine simulations, a highly efficient engine with a practical and realizable turbocharger concept resulted.

Numerical Investigation on Internal Flow Field of a Single-Stage Transonic Axial Compressor

2012 ◽  
Vol 15 (6) ◽  
pp. 85-91
Author(s):  
Ji-Han Song ◽  
Oh-Sik Hwang ◽  
Tae Choon Park ◽  
Byung-Jun Lim ◽  
Soo-Seok Yang ◽  
...  
Keyword(s):  
Flow Field ◽  
Numerical Investigation ◽  
Axial Compressor ◽  
Internal Flow ◽  
Single Stage ◽  
Transonic Axial Compressor

Numerical Investigation of Losses Due to Unsteady Effects in Axial Turbines

2003 ◽  
Author(s):  
Michael Moczala ◽  
Ernst von Lavante ◽  
Manuchehr Parvizinia
Keyword(s):  
High Pressure ◽  
Numerical Investigation ◽  
Research Work ◽  
Navier Stokes ◽  
Loss Assessment ◽  
Physical Explanation ◽  
Axial Turbine ◽  
Loss Coefficients ◽  
Axial Turbines ◽  
Unsteady Effects

Understanding of losses caused by unsteady effects is essential in efforts to improve the efficiency of modern turbomachines. In the present research work, the unsteady midspan flow in a typical high pressure axial turbine was investigated using a compressible Navier Stokes solver. The aim of this study was to take a closer look at trends in the loss behavior depending on several flow and geometry parameters as well as to give a physical explanation of these trends. Two different definitions of loss coefficients were also employed for the loss assessment and its suitability for evaluation of “unsteady losses” was discussed considering accuracy and physical aspects.

Numerical Study of Detonation Interaction with a Single-Stage Axial Turbine

2008 ◽  
Author(s):  
Ayaka Nango ◽  
Kazuaki Inaba ◽  
Takayuki Kojima ◽  
Makoto Yamamoto
Keyword(s):  
Numerical Study ◽  
Single Stage ◽  
Axial Turbine

Unsteady Interactions Between Axial Turbine and Nonaxisymmetric Exhaust Hood Under Different Operational Conditions

2011 ◽  
Vol 134 (4) ◽  
Author(s):  
Jing-Lun Fu ◽  
Jian-Jun Liu ◽  
Si-Jing Zhou
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Rotor Blade ◽  
Exhaust System ◽  
Single Stage ◽  
Exhaust Hood ◽  
Turbine Stage ◽  
Axial Turbine ◽  
Operational Conditions ◽  
Flow Interactions

The exhaust system in condensing steam turbines is used to recover leaving kinetic energy of the last stage turbine, while guiding the flow from turbine to condenser. The flows in the exhaust system and the turbine stage are fully coupled and inherently unsteady. The unsteady flow interactions between the turbine and the exhaust system have a strong impact on the blade loading or blade aerodynamic force. This paper describes the unsteady flow interactions between a single-stage axial turbine and an exhaust system. The experimental and numerical studies on the coupled flow field in the single-stage turbine and the exhaust hood model under different operational conditions have been carried out. Unsteady pressure at the turbine rotor blade, turbine outlet, and exhaust outcasing are measured and compared with the numerical prediction. The details of unsteady flow in the exhaust system with the whole annulus stator and rotor blade rows are simulated by employing the computational fluid dynamics software CFX-5. Results show that for the investigated turbine-exhaust configuration the influence of the flow field in the exhaust system on the unsteady blade force is much stronger than that of the stator and rotor interaction. The flow pattern in the exhaust system changes with the turbine operational condition, which influences the unsteady flow in the turbine stage further.

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