A loss analysis based on experimental data for a 99.0 mm radial inflow nozzled turbine with different stator throat areas

The results of experimental performance tests on a 99.0 mm radial inflow turbine with seven different nozzle throat areas were reported by the same authors in a previous publication (1). In order to perform a loss analysis, dividing the turbine losses between the stator and the rotor, a theoretical model of the stator loss was required. Several stator loss models were evaluated and the model described by Rohlik (9) was used as the basis for a loss analysis. Plots are given for the breakdown of losses at two operating speeds for each nozzle size. Both the stator and the rotor losses decreased markedly as the stator throat area increased towards a stator-rotor throat area ratio of 0.5. A significant step change in the magnitude of the rotor loss was evident at every stator size and appeared to correlate with the volumetric flowrate in the turbine exducer. Therefore a transition to a more efficient flow pattern in the exducer seemed to occur at higher flow-rates.

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Analysis of Radial Inflow Turbine Losses Operating with Supercritical Carbon Dioxide

Energies ◽

10.3390/en14123561 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3561

Author(s):

Antti Uusitalo ◽

Aki Grönman

Keyword(s):

Fluid Dynamic ◽

Dynamic Simulations ◽

Average Deviation ◽

Loss Analysis ◽

Specific Speed ◽

Loss Models ◽

Rotor Losses ◽

Radial Turbines ◽

Design Power ◽

Good Agreement

The losses of supercritical CO2 radial turbines with design power scales of about 1 MW were investigated by using computational fluid dynamic simulations. The simulation results were compared with loss predictions from enthalpy loss correlations. The aim of the study was to investigate how the expansion losses are divided between the stator and rotor as well as to compare the loss predictions obtained with the different methods for turbine designs with varying specific speeds. It was observed that a reasonably good agreement between the 1D loss correlations and computational fluid dynamics results can be obtained by using a suitable set of loss correlations. The use of different passage loss models led to high deviations in the predicted rotor losses, especially with turbine designs having the highest or lowest specific speeds. The best agreement in respect to CFD results with the average deviation of less than 10% was found when using the CETI passage loss model. In addition, the other investigated passage loss models provided relatively good agreement for some of the analyzed turbine designs, but the deviations were higher when considering the full specific speed range that was investigated. The stator loss analysis revealed that despite some differences in the predicted losses between the methods, a similar trend in the development of the losses was observed as the turbine specific speed was changed.

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Rotor Loss Analysis of Interior Permanent Magnet Motors Using Combination of 2-D and 3-D Finite Element Method

IEEE Transactions on Magnetics ◽

10.1109/tmag.2009.2012817 ◽

2009 ◽

Vol 45 (3) ◽

pp. 1772-1775 ◽

Cited By ~ 31

Author(s):

K. Yamazaki ◽

Y. Kanou

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Permanent Magnet ◽

Permanent Magnet Motors ◽

Loss Analysis ◽

Interior Permanent Magnet ◽

Rotor Loss ◽

Element Method

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Comparing the development of Local Industrial Strategies across the Northern Powerhouse: Key emerging issues

Local Economy The Journal of the Local Economy Policy Unit ◽

10.1177/0269094220959299 ◽

2020 ◽

Vol 35 (4) ◽

pp. 297-315

Author(s):

John Shutt ◽

Joyce Liddle

Keyword(s):

Economic Development ◽

Institutional Arrangements ◽

Step Change ◽

Information Resources ◽

The North ◽

Conservative Government ◽

Shared Information ◽

Significant Step ◽

Emerging Issues ◽

The Uk

Will the UK Industrial Strategy deliver anything substantial to the North of England? This article examines the faltering steps taken to develop Local Industrial Strategies by Local Enterprise Partnerships and Mayoral Combined Authorities and argues Place Leadership and Industrial Strategy will both need to be substantially re-galvanised after COVID 19. It is also still not clear if a significant step change can be made by the Johnson Conservative government of 2019, which will have a major impact on Northern economies. Agencies’ capacity to intervene in the Northern economy and deliver is a major issue, alongside stronger leadership. Analytically the paper uses theory on Multi-Sectoral Collaboration and Place Leadership to show how uniqueness of place, past and current interpersonal connections and networks can facilitate or frustrate economic development. Place leaders must create institutional arrangements, seek agreement over visions, objectives and strategies, otherwise the lack of shared information, resources, activities and capabilities lead to ‘contestation’ over space and action. We analyse the levels of cohesion or contestation in four different localities as each develops a Local Industrial Strategy.

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Experimental Performance Tests of Magnetic-frictional Dampers to Embody a Smart Damper

Korean Society of Hazard Mitigation ◽

10.9798/kosham.2014.14.5.43 ◽

2014 ◽

Vol 14 (5) ◽

pp. 43-48

Author(s):

Eunsoo Choi ◽

Gyuchan Choi

Keyword(s):

Performance Tests ◽

Experimental Performance

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Demonstration of Fluidic Throat Skewing for Thrust Vectoring in Structurally Fixed Nozzles

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1361109 ◽

2001 ◽

Vol 123 (3) ◽

pp. 502-507 ◽

Cited By ~ 26

Author(s):

P. J. Yagle ◽

D. N. Miller ◽

K. B. Ginn ◽

J. W. Hamstra

Keyword(s):

Conceptual Development ◽

Discharge Coefficient ◽

Companion Paper ◽

Nozzle Throat ◽

Thrust Coefficient ◽

Thrust Vectoring ◽

Flow Rates ◽

Critical Design ◽

Design Variables ◽

Nozzle Pressure

The experimental demonstration of a fluidic, multiaxis thrust vectoring (MATV) scheme is presented for a structurally fixed, afterburning nozzle referred to as the conformal fluidic nozzle (CFN). This concept for jet flow control features symmetric injection around the nozzle throat to provide throttling for jet area control, and asymmetric injection to subsonically skew the sonic plane for jet vectoring. The conceptual development of the CFN was presented in a companion paper (Miller et al. [1]). In that study, critical design variables were shown to be the flap length and expansion area ratio of the nozzle, and the location, angle, and distribution of injected flow. Measures of merit were vectoring capability, gross thrust coefficient, and discharge coefficient. A demonstration of MATV was conducted on a 20 percent scale CFN test article across a range of nozzle pressure ratios (NPR), injector flow rates, and flow distributions. Both yaw and pitch vector angles of greater than 8 deg were obtained at NPR of 5.5. Yaw vector angles greater than 10 deg were achieved at lower NPR. Values of thrust coefficient for the CFN generally exceeded published measurements of shock-based vectoring methods. In terms of vectoring effectiveness (ratio of vector angle to percent injected flow), fluidic throat skewing was found to be comparable to shock-based vectoring methods.

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Bio-tower Application for Wastewater Treatment

Journal of Engineering Research and Reports ◽

10.9734/jerr/2020/v11i117048 ◽

2020 ◽

pp. 1-7

Author(s):

Klaus Doelle ◽

Yue Qin ◽

Qian Wang

Keyword(s):

Wastewater Treatment ◽

Chemical Oxygen Demand ◽

Total Phosphorus ◽

Municipal Wastewater ◽

Oxygen Demand ◽

Growth Media ◽

Performance Tests ◽

Flow Rates ◽

Batch Type ◽

Phosphorus Reduction

The study tested the performance of a batch-type recirculating laboratory scale bio-tower for the treatment of municipal wastewater. Performance tests were done with a HACH DR-1900 spectrophotometer include chemical oxygen demand, total phosphorus and nitrogen ammonia. This study showed that the recirculated laboratory type bio-tower containing 0.276 ft3 (0.008 m3) of polypropylene growth media with a surface area of 6.624 ft2 (0.615 m2) can reduce the chemical oxygen demand between 70% to 87%. NH3-N reduction was found to be between 94% to 96%, and total phosphorus reduction was between 69% and 87% for flow rates of 0.6 l/min to 1.5 l/min.

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A Study of the Behaviour of Flow in a Diagonal-Flow Turbomachine

Volume 1: Turbomachinery ◽

10.1115/96-gt-061 ◽

1996 ◽

Author(s):

Arjun Sarathi Ray

Keyword(s):

Fluid Dynamic ◽

Characteristic Curve ◽

Axial Flow ◽

Time History ◽

Rotating Stall ◽

Flow Coefficient ◽

Flow Measurements ◽

Flow Rates ◽

Rotor Losses ◽

Reduced Flow

Experiments were conducted on a diagonal-flow machine to study the behaviour of flow. Measurements showed that at reduced flow rates, reversal of flow occurs near the tip upstream of the rotor and near the hub downstream. At high flow rates, the flow reverses near tip at downstream only. In fact, there is only a limited regime of operation where the flow is not reversed before or after the impeller. The best fluid-dynamic efficiency was observed to be midway of this non-reversed flow regime. Through-flow solutions of the mean hub-to-tip streamsurface were carried out by streamline curvature computation and compared with experimental results. The comparison showed good agreement of the predicted values with the experimental data. However, attempts to compare theoretical estimates of rotor losses with experimental measurements showed that the existing loss models are inadequate for loss prediction and further work is required in this direction. The head-flow characteristic of the machine showed a droop at reduced flow rates, typical of what one usually notices in an axial-flow machine with the onset of blade stall. Study of the time history of velocity downstream of rotor illustrated that unlike rotating ‘stall-cells’ in axial-flow machines, the blade stall in the present case did not possess any regular pattern nor any unique speed of propagation. Near the hub at downstream of rotor, where the flow finally reverses upon reduction of flow rate, the stall appeared as patches of ‘blockage’ type disturbance over an otherwise systematic train of blade wakes when the flow coefficient reaches a value where the droop in the characteristic curve starts.

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