Simulation Strategy for Film-Cooled Multistage Turbine Design and Analysis

2013 ◽  
Vol 29 (6) ◽  
pp. 1495-1498 ◽  
Author(s):  
Joshua Gottlieb ◽  
Roger L. Davis ◽  
John P. Clark
Keyword(s):  
Multistage Turbine ◽  
Simulation Strategy ◽  
Turbine Design

Origins of Loss Within a Multistage Turbine Environment Under Conditions of Partial Admission

1997 ◽  
Author(s):  
Guy R. Wakeley ◽  
Ian Potts
Keyword(s):  
Pressure Ratio ◽  
Axial Flow ◽  
Navier Stokes ◽  
Multi Stage ◽  
Air Turbine ◽  
Partial Admission ◽  
Multistage Turbine ◽  
Bending Stresses ◽  
Swallowing Capacity ◽  
Turbine Design

A partially admitted first stage is routinely used in a wide variety of turbo-machines to match the turbine swallowing capacity to the cycle pressure ratio over a range of outputs. Such a configuration is often favoured for applications in which optimised part-load efficiency is a design requirement. Partial admission is achieved by dividing the stator row into discrete arcs, each of which can be separately supplied with fluid. This arrangement creates circumferential discontinuities and considerable unsteadiness in the flow field within the intra-stage gap, and this unsteadiness can propagate through several downstream rows of fully admitted blading. In the current work an unsteady, multi-stage, multi-passage, Navier-Stokes solver has been validated against experimental results from a multistage axial flow air turbine. Interstage traverses of static and total pressure are shown to agree well with the CFD predictions, and the measured and predicted partial admission loss is compared with published correlations. It is further shown that the operating point of downstream stages is influenced by the degree of partial admission in the first stage. Additionally, increased alternating blade bending stresses are predicted. These phenomena are not included in any published turbine design methods, and are discussed within the context of large output steam turbine optimisation.

scholarly journals Pulsed Flow Turbine Design Recommendations

2021 ◽  
Vol 6 (3) ◽  
pp. 24
Author(s):  
Florian Hermet ◽  
Nicolas Binder ◽  
Jérémie Gressier ◽  
Gonzalo Sáez-Mischlich
Keyword(s):  
Design Of Experiments ◽  
Performance Indicator ◽  
Influential Factors ◽  
Factor Level ◽  
Viscous Effects ◽  
Inviscid Flows ◽  
Screening Design ◽  
Pulsed Flow ◽  
Number Of Factors ◽  
Turbine Design

A preliminary analysis of turbine design, fit for pulsed flow, is proposed in this paper. It focuses on an academic 2D configuration using inviscid flows, since pressure loads due to wave propagation are several orders of magnitude higher than friction and viscous effects do not significantly impinge on the inviscid part, as previously shown by Hermet, 2021. As such, a large parametric study was carried out using the design of experiments methodology. A performance indicator adapted to unsteady environment is carefully defined before detailing the factors chosen for the design of experiments. Since the number of factors is substantial, a screening design to identify the factors influence on the output is first established. The non-influential factors are then omitted in a more quantitative study of the output law. The surface response calculation allows determining the factor level favouring the best output. Consequently, the main trends in the turbine design driven by a pulsed flow can be stated.

scholarly journals Radial Turbine Design for Solar Chimney Power Plants

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 674
Author(s):  
Paul Caicedo ◽  
David Wood ◽  
Craig Johansen
Keyword(s):  
Power Plants ◽  
Reference Frames ◽  
Three Dimensional ◽  
Discrete Ordinates ◽  
Large Area ◽  
Solar Chimney ◽  
Cfd Simulations ◽  
Radial Turbine ◽  
Design Changes ◽  
Turbine Design

Solar chimney power plants (SCPPs) collect air heated over a large area on the ground and exhaust it through a turbine or turbines located near the base of a tall chimney to produce renewable electricity. SCPP design in practice is likely to be specific to the site and of variable size, both of which require a purpose-built turbine. If SCPP turbines cannot be mass produced, unlike wind turbines, for example, they should be as cheap as possible to manufacture as their design changes. It is argued that a radial inflow turbine with blades made from metal sheets, or similar material, is likely to achieve this objective. This turbine type has not previously been considered for SCPPs. This article presents the design of a radial turbine to be placed hypothetically at the bottom of the Manzanares SCPP, the only large prototype to be built. Three-dimensional computational fluid dynamics (CFD) simulations were used to assess the turbine’s performance when installed in the SCPP. Multiple reference frames with the renormalization group k-ε turbulence model, and a discrete ordinates non-gray radiation model were used in the CFD simulations. Three radial turbines were designed and simulated. The largest power output was 77.7 kW at a shaft speed of 15 rpm for a solar radiation of 850 W/m2 which exceeds by more than 40 kW the original axial turbine used in Manzanares. Further, the efficiency of this turbine matches the highest efficiency of competing turbine designs in the literature.

scholarly journals Turbine design dependency to turbulence: An experimental study of three scaled tidal turbines

2021 ◽  
Vol 234 ◽  
pp. 109035
Author(s):  
Myriam Slama ◽  
Grégory Pinon ◽  
Charifa El Hadi ◽  
Michael Togneri ◽  
Benoît Gaurier ◽  
...  
Keyword(s):  
Experimental Study ◽  
Tidal Turbines ◽  
Turbine Design

scholarly journals Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Low Noise ◽  
Closed Cycle ◽  
Propulsion Systems ◽  
Component Design ◽  
Readiness Level ◽  
Aerial Vehicle ◽  
Turbine Design

When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.

Implementation of tunable resonators in planar groove gap waveguide technology

2021 ◽  
pp. 1-7
Author(s):  
Titus Oyedokun ◽  
Riana H. Geschke ◽  
Tinus Stander
Keyword(s):  
Printed Circuit Board ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Resonant Cavity ◽  
Circuit Board ◽  
Resonant Cavities ◽  
Tunable Resonators ◽  
Simulation Strategy ◽  
Dc Bias ◽  
Continuous Frequency

Abstract We present a tunable planar groove gap waveguide (PGGWG) resonant cavity at Ka-band. The cavity demonstrates varactor loading and biasing without bridging wires or annular rings, as commonly is required in conventional substrate-integrated waveguide (SIW) resonant cavities. A detailed co-simulation strategy is also presented, with indicative parametric tuning data. Measured results indicate a 4.48% continuous frequency tuning range of 32.52–33.98 GHz and a Qu tuning range of 63–85, corresponding to the DC bias voltages of 0–16 V. Discrepancies between simulated and measured results are analyzed, and traced to process variation in the multi-layer printed circuit board stack, as well as unaccounted varactor parasitics and surface roughness.

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