scholarly journals Influence of Outlets Port Design on The Tesla Turbine Performance

2021 ◽  
Vol 2129 (1) ◽  
pp. 012074
Author(s):  
Sufi Halim ◽  
Md Tasyrif Abdul Rahman ◽  
Anas Abdul Rahman ◽  
Muhammad Adi Hilmi Adnan ◽  
Muhammad Hafizi Azuzin ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Design Process ◽  
Computer Software ◽  
Test Model ◽  
Virtual Design ◽  
New Techniques ◽  
Future Studies ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
Port Design

Abstract The boundary layer turbine known as Tesla Turbine invented long ago but has failed to be commercialized and replaced by bladed turbines. In this paper, two new techniques for improving the turbine have been proposed. A test model of the proposed boundary layer turbine has been fabricated made and tested under different conditions. The design process includes producing a virtual design and simulation of the turbine using computer software. The proposed designs were fabricated and then tested to analyse results such as speed produced, power produced, and the turbine efficiency. From this study, the proposed turbine designs manage to achieve 18% and 69% efficiency. The findings of this study will serve as a reference for future studies in the generation of power through an alternative powered driven turbine.

Calculated Design Data for the Multiple-Disk Turbine Using Incompressible Fluid

1974 ◽  
Vol 96 (3) ◽  
pp. 252-258 ◽  
Author(s):  
M. J. Lawn ◽  
W. Rice
Keyword(s):  
Pressure Drop ◽  
Incompressible Fluid ◽  
Design Process ◽  
Total Pressure ◽  
Design Data ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
Fluid Properties ◽  
Disk Friction ◽  
Turbine Exhaust

Earlier analyses of the laminar radially inward throughflow of Newtonian incompressible fluid between parallel corotating disks have been used to calculate the performance of multiple-disk turbines using such flow passages as the rotor. Such turbines are characterized by certain dimensionless parameters and a large number of computerized calculations has enabled preparation of turbine performance maps for turbines idealized as having no losses external to the rotor (except for assumed zero pressure recovery in the turbine exhaust). These maps show the quantitative dependence of turbine efficiency, total pressure and delivered power on the turbine geometry and speed, the turbine nozzle direction and pressure drop, and on the fluid properties; full admission around the periphery of the rotor is assumed. Conventional loss information for the nozzles, and conventional bearing, seal and “disk friction” loss information, must be applied in the design process to provide prediction of actual turbine performance and comparison with conventional turbines.

The design of modular oil tank: A new design process model

2020 ◽  
Vol 15 ◽  
Author(s):  
Jin Li ◽  
Xingsheng Jiang ◽  
Jingye Li ◽  
Yadong Zhao ◽  
Xuexing Li
Keyword(s):  
Product Design ◽  
Design Process ◽  
Process Model ◽  
Mechanical Design ◽  
Computer Software ◽  
Reference Value ◽  
Fuel Tank ◽  
Design Quality ◽  
Design Time ◽  
Design Process Model

Background: In the whole design process of modular fuel tank, there are some unreasonable phenomena. As a result, there are some defects in the design of modular fuel tank, and the function does not meet the requirements in advance. This paper studies this problem. Objective: Through on-the-spot investigation of the factory, a mechanical design process model is designed. The model can provide reference for product design participants on product design time and design quality, and can effectively solve the problem of low product design quality caused by unreasonable product design time arrangement. Methods: After sorting out the data from the factory investigation, computer software is used to program, simulate the information input of mechanical design process, and the final reference value is got. Results: This mechanical design process model is used to guide the design and production of a new project, nearly 3 months ahead of the original project completion time. Conclusion: This mechanical design process model can effectively guide the product design process, which is of great significance to the whole mechanical design field.

Study on Coordination of Heterogeneous Databases

2014 ◽  
Vol 608-609 ◽  
pp. 336-342
Author(s):  
Huan Liu
Keyword(s):  
Hot Spot ◽  
Computer Software ◽  
Heterogeneous Databases ◽  
Important Research ◽  
Heterogeneous Database ◽  
New Techniques ◽  
Directory Service ◽  
New Development ◽  
Development Direction ◽  
New Applications

How to coordinate heterogeneous database to realize sharing and consistency of information not only is an important research subject in the database filed, but also is an emerging research hot spot in the field of database system. As a new development direction of computer software, it applies some new techniques to integrate the existing systems to develop new applications. The paper analyzes CSCW, XML, JDBC and heterogeneous database, and proposes a solution of heterogeneous database. The solution absorbs the thoughts of database meta data, middle ware and LDAP directory service.

Contraction-by-contraction V̇o2 and computer-controlled pump perfusion as novel techniques to study skeletal muscle metabolism in situ

2010 ◽  
Vol 108 (3) ◽  
pp. 705-712 ◽  
Author(s):  
Andrés Hernández ◽  
Matthew L. Goodwin ◽  
Nicola Lai ◽  
Marco E. Cabrera ◽  
James R. McDonald ◽  
...  
Keyword(s):  
Blood Flow ◽  
Moving Average ◽  
Computer Software ◽  
Muscle Metabolism ◽  
New Techniques ◽  
Muscle Oxygen ◽  
Flow Adjustment ◽  
Train Duration ◽  
Muscle Complex

The purpose of this research was to develop new techniques to 1) rapidly sample venous O2 saturation to determine contraction-by-contraction oxygen uptake (V̇o2), and 2) precisely control the rate and pattern of blood flow adjustment from one chosen steady state to another. An indwelling inline oximeter probe connected to an Oximetrix 3 meter was used to sample venous oxygen concentration ([O2]) (via fractional saturation of Hb with O2). Data from the Oximetrix 3 were filtered, deconvolved, and processed by a moving average second by second. Computer software and a program written in-house were used to control blood flow with a peristaltic pump. The isolated canine gastrocnemius muscle complex (GS) in situ was utilized to test these techniques. A step change in metabolic rate was elicited by stimulating GS muscles via their sciatic nerves (supramaximal voltage, 8 V; 50 Hz, 0.2-ms pulse width; train duration 200 ms) at a rate of either 1 contraction/2 s, or 2 contractions/3 s. With arterial [O2] maintained constant, blood flow and calculated venous [O2] were averaged over each contraction cycle and used in the Fick equation to calculate contraction-by-contraction V̇o2. About 5–8 times more data points were obtained with this method compared with traditional manual sampling. Software-controlled pump perfusion enabled the ability to mimic spontaneous blood flow on-kinetics (τ: 14.3 s) as well as dramatically speed (τ: 2.0 s) and slow (τ: 63.3 s) on-kinetics. These new techniques significantly improve on existing methods for mechanistically altering blood flow kinetics as well as accurately measuring muscle oxygen consumption kinetics during transitions between metabolic rates.

scholarly journals Study of the air-sea interactions at the mesoscale: the SEMAPHORE experiment

1996 ◽  
Vol 14 (9) ◽  
pp. 986-1015 ◽  
Author(s):  
L. Eymard ◽  
S. Planton ◽  
P. Durand ◽  
C. Le Visage ◽  
P. Y. Le Traon ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Ocean Circulation ◽  
Wave Model ◽  
Heat Fluxes ◽  
Sea Surface ◽  
Upper Ocean ◽  
Test Model ◽  
Model Simulations ◽  
Drifting Buoys

Abstract. The SEMAPHORE (Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale) experiment has been conducted from June to November 1993 in the Northeast Atlantic between the Azores and Madeira. It was centered on the study of the mesoscale ocean circulation and air-sea interactions. The experimental investigation was achieved at the mesoscale using moorings, floats, and ship hydrological survey, and at a smaller scale by one dedicated ship, two instrumented aircraft, and surface drifting buoys, for one and a half month in October-November (IOP: intense observing period). Observations from meteorological operational satellites as well as spaceborne microwave sensors were used in complement. The main studies undertaken concern the mesoscale ocean, the upper ocean, the atmospheric boundary layer, and the sea surface, and first results are presented for the various topics. From data analysis and model simulations, the main characteristics of the ocean circulation were deduced, showing the close relationship between the Azores front meander and the occurrence of Mediterranean water lenses (meddies), and the shift between the Azores current frontal signature at the surface and within the thermocline. Using drifting buoys and ship data in the upper ocean, the gap between the scales of the atmospheric forcing and the oceanic variability was made evident. A 2 °C decrease and a 40-m deepening of the mixed layer were measured within the IOP, associated with a heating loss of about 100 W m-2. This evolution was shown to be strongly connected to the occurrence of storms at the beginning and the end of October. Above the surface, turbulent measurements from ship and aircraft were analyzed across the surface thermal front, showing a 30% difference in heat fluxes between both sides during a 4-day period, and the respective contributions of the wind and the surface temperature were evaluated. The classical momentum flux bulk parameterization was found to fail in low wind and unstable conditions. Finally, the sea surface was investigated using airborne and satellite radars and wave buoys. A wave model, operationally used, was found to get better results compared with radar and wave-buoy measurements, when initialized using an improved wind field, obtained by assimilating satellite and buoy wind data in a meteorological model. A detailed analysis of a 2-day period showed that the swell component, propagating from a far source area, is underestimated in the wave model. A data base has been created, containing all experimental measurements. It will allow us to pursue the interpretation of observations and to test model simulations in the ocean, at the surface and in the atmospheric boundary layer, and to investigate the ocean-atmosphere coupling at the local and mesoscales.

The Effect of Stator-Rotor Hub Sealing Flow on the Mainstream Aerodynamics of a Turbine

2006 ◽  
Author(s):  
Kevin Reid ◽  
John Denton ◽  
Graham Pullan ◽  
Eric Curtis ◽  
John Longley
Keyword(s):  
Steady State ◽  
Entropy Generation ◽  
Flow Rate ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Flow Conditions ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
Mainstream Flow ◽  
Flow Interactions

An investigation into the effect of stator-rotor hub gap sealing flow on turbine performance is presented. Efficiency measurements and rotor exit area traverse data from a low speed research turbine are reported. Tests carried out over a range of sealing flow conditions show that the turbine efficiency decreases with increasing sealant flow rate but that this penalty is reduced by swirling the sealant flow. Results from time-accurate and steady-state simulations using a three-dimensional multi-block RANS solver are presented with particular emphasis paid to the mechanisms of loss production. The contributions toward entropy generation of the mixing of the sealant fluid with the mainstream flow and of the perturbed rotor secondary flows are assessed. The importance of unsteady stator wake/sealant flow interactions is also highlighted.

The Effect of Clearance Flow of Variable Area Nozzles on Radial Turbine Performance

2008 ◽  
Author(s):  
Hideaki Tamaki ◽  
Shinya Goto ◽  
Masaru Unno ◽  
Akira Iwakami
Keyword(s):  
Flow Field ◽  
Tip Clearance ◽  
Leakage Flow ◽  
Specific Work ◽  
Nozzle Vane ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
Setting Angle ◽  
Clearance Flow ◽  
1D Model

The flow behind the variable area nozzle for radial turbines was measured with a 3-hole yaw probe and calculated with CFD. Two nozzle throat-areas were investigated: the smallest and the largest opening for the variable nozzle. Test results agreed with the calculated results qualitatively. The leakage flow through the tip clearance of the nozzle vane significantly affected the flow field downstream of the nozzle vane with the smallest opening. However, the effect on leakage flow on the flow field downstream of the nozzle vane with the largest opening was very weak. In the flow field of the largest opening nozzle, the effect of wake s dominant. The effect of the clearance of the nozzle vane on the turbine performance was estimated by a 1D-model and the strong influence on the turbine efficiency was confirmed at smallest opening. The flow fields in the impeller downstream of the nozzle vane at the smallest opening with and without the nozzle clearance were investigated with CFD. The setting angle of the nozzle vane without clearance was adjusted to match the operating point of the turbine with the nozzle clearance. In order to extract the specific work from the impeller, the nozzle vane with the vane clearance requires the larger vane setting angle than that without clearance. The increase of the vane setting angle increases the incidence loss and deteriorates turbine efficiency.

Boundary Layer Studies on Highly Loaded Cascades using Heated Thin Films and a Traversing Probe

1981 ◽  
Vol 103 (1) ◽  
pp. 237-246 ◽  
Author(s):  
M. L. G. Oldfield ◽  
R. Kiock ◽  
A. T. Holmes ◽  
C. G. Graham
Keyword(s):  
Boundary Layer ◽  
Transfer Rate ◽  
High Speed ◽  
Blade Profile ◽  
Aerodynamic Loading ◽  
Turbine Efficiency ◽  
Surface Transition ◽  
Turbine Vanes ◽  
Constant Temperature Anemometer ◽  
Highly Loaded

In the continuing quest for increased turbine efficiency, the part played by blade profile shape remains crucial. Three turbine vanes with successively increased aerodynamic loading were tested in the High Speed Cascade Wind Tunnel at DFVLR Braunschweig. In addition to wake traverses, measurements of the boundary layer behavior were made. These consisted of (1) use of a constant temperature anemometer to measure the fluctuating heat transfer rate on an array of thin film platinum thermometers deposited on the vanes and (2) a flattened, traversing pitot probe held against the vane surface. Transition measurement by these techniques is described.

On the transient response of the turbulent boundary layer inception in compressible flows

2018 ◽  
Vol 850 ◽  
pp. 1117-1141 ◽  
Author(s):  
J. Saavedra ◽  
G. Paniagua ◽  
S. Lavagnoli
Keyword(s):  
Boundary Layer ◽  
Flow Control ◽  
Boundary Layers ◽  
Thermal Boundary Layer ◽  
Free Stream ◽  
Test Model ◽  
Additional Time ◽  
Time Required ◽  
Momentum Boundary Layer

The behavioural characteristics of thermal boundary layer inception dictate the efficiency of heat exchangers and the operational limits of fluid machinery. The specific time required by the thermal boundary layer to be established is vital to optimize flow control strategies, as well as the thermal management of systems exposed to ephemeral phenomena, typically on the millisecond scale. This paper presents the time characterization of the momentum and thermal boundary layer development in transient turbulent compressible air flows. We present a new framework to perform such estimations based on detailed unsteady Reynolds averaged Navier–Stokes simulations that may be extended to higher fidelity simulations. First of all, the aerodynamic boundary layer initiation is described using adiabatic simulations. Additional numerical calculations were then performed by setting the isothermal wall condition to evaluate the additional time required by the thermal boundary layer to establish after the aerodynamic boundary layer reaches its steady state. Finally, full conjugate simulations were executed to compute the warm up effect of the solid during the blowdown of a hot fluid over a colder metallic test model. The transient performance of the turbulent thermal and momentum boundary layers is quantified through numerical simulations of air blowdown over a flat plate for different mainstream flow conditions. The effects of Reynolds number, free stream velocity, transient duration, test article length and free stream temperature were independently assessed, to then define a mathematical expression of the momentum boundary layer settlement. This paper presents a novel numerical correlation of the additional time required by the thermal boundary layer to be stablished after the settlement of the momentum boundary layer. The time scales of the aerodynamic and thermal boundary layers are presented as a function of relevant non-dimensional numbers, as well as the description of the response of the near wall flow to sudden free stream changes. The characterization of the boundary layer mechanisms discussed in this paper contribute to the establishment of an evidence-based foundation for advances in the field of flow control.

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