Analysis of influence of guide vane wrap angle and blade number on propulsive performance of a water jet propulsor

2021 ◽  
Author(s):  
Wei Han ◽  
Wenjuan Xie ◽  
Rennian Li ◽  
Haojie Wang ◽  
Yanzhi Pan ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Guide Vane ◽  
Operating Conditions ◽  
Guide Vanes ◽  
Propulsion Efficiency ◽  
Main Research ◽  
Advantages And Disadvantages ◽  
Propulsion Performance ◽  
Calculation Results ◽  
Wrap Angle

In this paper, the propulsion performance of a screw mixed-flow jet propulsion pump is studied systematically. The optimum thrust performance is achieved by changing the geometrical dimensions of the guide vanes. Under the condition of keeping other parameters unchanged, the operating conditions of the pump can be effectively adjusted by changing the number of guide vanes and wrap angle. The focus of this paper is on the presentation and demonstration of a strategy that takes the number of guide vanes and wraps angle as the main research object and its propulsion efficiency as the main reference index to analyze the advantages and disadvantages of each working condition in detail. The CFD numerical simulation technology has been used for numerical calculation. The simulation results are compared with the experimental results, and the numerical calculation results are in good agreement with the experimental values. The results show that the kinetic energy of the propulsion pump increases with the number of guide vane blades and the angle of wrap angle. The increase of guide angle and the number of blades will reduce the overall propulsion efficiency of the propeller. Finally, a mathematical model of propeller efficiency with the number of guide vane blades and the angle coefficient of guide vanes is established.

Nozzle Guide Vane Static Strip Seals

2006 ◽  
Author(s):  
Arash Farahani ◽  
Peter Childs
Keyword(s):  
Gas Turbines ◽  
Guide Vane ◽  
Main Stream ◽  
Guide Vanes ◽  
Advantages And Disadvantages ◽  
Air System ◽  
Improved Performance ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Assembly Constraints

Sealing of components where there is no relative motion between the elements concerned remains a significant challenge in many gas turbine engine applications. Loss of sealing and cooling air from the internal air system through seals impacts on specific fuel consumption and can lead to undesirable flow interactions with resultant cost implications. For gas turbines, various strip seal types have been developed for use between Nozzle Guide Vanes in order to limit the flow of gas between the main stream annulus and the internal air system. Many different types of design have been proposed for overcoming strip seal problems such as misalignment of the grooves due to manufacturing and assembly constraints. In this paper various methods, with a particular focus on patents, for minimising the amount of leakage caused by such problems for strip seals between nozzle guide vanes are reviewed. By considering the advantages and disadvantages of each technique it is concluded that although apparently new strip seal designs for NGVs have improved performance, none of them can be considered to be ideal. This paper reviews the techniques and makes recommendations for future designs.

Variable Inlet Guide Vane Effect on Centrifugal Compressor Performance in Wet Gas Flow

2016 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Guide Vanes ◽  
Wet Gas ◽  
Compressor Performance

The introduction of variable inlet guide vanes (VIGVs) upfront of a compressor stage affects performance and permits tuning for off-design conditions. This is of great interest for emerging technology related to subsea compression. Unprocessed gas from the wellhead will contain liquid condensate, which affects the operational condition of the compressor. To investigate the effect of guide vanes on volume flow and pressure ratio in a wet gas compressor, VIGVs are implemented upfront of a centrifugal compressor stage to control the inlet flow direction. The guide vane geometry and test rig setup have previous been presented. This paper documents how changing the VIGV setting affects compressor performance under dry and wet operating conditions. The reduced performance effect and operating range at increased liquid content are of specific interest. Also documented is the change in the VIGV effect relative to the setting angle.

Lateral Fluid Forces on Whirling Centrifugal Impeller (1st Report: Theory)

1987 ◽  
Vol 109 (2) ◽  
pp. 94-99 ◽  
Author(s):  
H. Shoji ◽  
H. Ohashi
Keyword(s):  
Potential Flow ◽  
Guide Vane ◽  
Flow Theory ◽  
Operating Conditions ◽  
Centrifugal Impeller ◽  
Flow Rates ◽  
Guide Vanes ◽  
Fluid Forces ◽  
Damping Effect ◽  
Whirling Motion

Lateral fluid forces acting on a rotating centrifugal impeller in whirling motion are analyzed using unsteady potential flow theory. Impellers operating in diffusers with and without vanes are modeled and the fluid forces calculated for different whirl speeds and flow rates. The influences of these parameters are clarified by parametric calculations. The results for whirling impellers operating in vaneless diffusers show that the fluid forces exert a damping effect on the rotor whirling motion at all operating conditions. The results for impellers operating in vaned diffusers or guide vanes show that the time averaged values of fluid forces remain almost unchanged, while there are significant instantaneous fluctuations due to the impeller/guide vane interactions.

Investigation on the Internal Cooling of Two-Passage Channels With Parallel Ribs and Guide Vanes

2019 ◽  
Author(s):  
Ryoichi S. Amano ◽  
Mandana S. Saravani ◽  
Nicholas DiPasquale
Keyword(s):  
Heat Transfer ◽  
Guide Vane ◽  
Constant Heat Flux ◽  
Operating Conditions ◽  
Internal Cooling ◽  
Flux Boundary Condition ◽  
Guide Vanes ◽  
Flow And Heat Transfer ◽  
Speed Up ◽  
Dynamics Simulations

Abstract The present work investigates the effects of various guide vane designs on the heat transfer enhancement of rotating U-Duct configuration with parallel 45-deg ribs. The ribs were installed on the bottom wall of the channel which has a constant heat flux boundary condition. The channel has a square cross-section with a 5.08 cm (2 in) hydraulic diameter. The first and second passes are 514 mm and 460 mm, respectively. The range of Reynolds number for turbulent flow is up to 35,000. The channel rotates in various speed up to 600 rpm which brings the maximum rotation number of 0.75. Several computational fluid dynamics simulations are carried out for this study to understand the effect of guide vanes on flow and heat transfer in serpentine channels under various operating conditions.

On Kinematic Relaxation and Deposition of Water Droplets in the Last Stages of Low Pressure Steam Turbines

2013 ◽  
Vol 136 (7) ◽  
Author(s):  
J. Starzmann ◽  
P. Kaluza ◽  
M. V. Casey ◽  
F. Sieverding
Keyword(s):  
Turbulent Diffusion ◽  
Guide Vane ◽  
Operating Conditions ◽  
Three Dimensions ◽  
Steam Turbines ◽  
Droplet Deposition ◽  
Simple Method ◽  
Advantages And Disadvantages ◽  
Droplet Sizes ◽  
Last Stage

In the first part of the paper steady two-phase flow predictions have been performed for the last stage of a model steam turbine to examine the influence of drag between condensed fog droplets and the continuous vapor phase. In general, droplets due to homogeneous condensation are small and thus kinematic relaxation provides only a minor contribution to the wetness losses. Different droplet size distributions have been investigated to estimate at which size interphase friction becomes more important. The second part of the paper deals with the deposition of fog droplets on stator blades. Results from several references are repeated to introduce the two main deposition mechanisms which are inertia and turbulent diffusion. Extensive postprocessing routines have been programmed to calculate droplet deposition due to these effects for a last stage stator blade in three-dimensions. In principle the method to determine droplet deposition by turbulent diffusion equates to an approach for turbulent pipe flows and the advantages and disadvantages of this relatively simple method are discussed. The investigation includes the influence of different droplet sizes on droplet deposition rates and shows that for small fog droplets turbulent diffusion is the main deposition mechanism. If the droplets size is increased inertial effects become more and more important and for droplets around 1 μm inertial deposition dominates. Assuming realistic droplet sizes the overall deposition equates to about 1% to 3% of the incoming wetness for the investigated guide vane at normal operating conditions.

Experimental and Numerical Investigations of Flowpath Profiling on Secondary Flow Losses in a Turbine Control Stage

2013 ◽  
Author(s):  
Nils Moser ◽  
Peter Steinhoff ◽  
Franz Joos
Keyword(s):  
Pressure Distribution ◽  
Secondary Flow ◽  
Guide Vane ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Formation Mechanisms ◽  
Guide Vanes ◽  
Numerical Investigations ◽  
Control Stage ◽  
Wide Range

The numerically and experimentally investigated industrial steam turbine control stage is derived from a real design. Due to the production process and costs of the guide vanes for control stages of steam turbines the flowpath profiling is rotationally symmetric. However the combination of the two-dimensional shroud contour and the flow deflection in the guide vane results in a fully three-dimensional end wall contour having a strong influence on the secondary flow features in the turbine control stage. To obtain an improved profile for the nozzle shroud the reduction of the total pressure loss over the guide vanes is taken as an optimization criterion. The three-dimensional contour generates a diffuser flowpath between the suction and the pressure side of two guide vanes perpendicular to the main flow direction. This diffuser geometry affects the pressure distribution over the guide vane and therefore the formation mechanisms of secondary flows. For the experimental and numerical investigations a baseline shroud design and two additional profiled contours are analyzed in detail. The control stage test rig is operated with air and is capable to represent a wide range of operating conditions. The measurements show a considerable increase of the stage efficiency and power output. The effect of the flowpath profiling on the pressure distribution over the guide vane is clearly proved.

On Kinematic Relaxation and Deposition of Water Droplets in the Last Stages of Low Pressure Steam Turbines

2013 ◽  
Author(s):  
J. Starzmann ◽  
P. Kaluza ◽  
M. V. Casey ◽  
Frank Sieverding
Keyword(s):  
Turbulent Diffusion ◽  
Guide Vane ◽  
Operating Conditions ◽  
Three Dimensions ◽  
Steam Turbines ◽  
Droplet Deposition ◽  
Simple Method ◽  
Advantages And Disadvantages ◽  
Droplet Sizes ◽  
Last Stage

In the first part of the paper steady two-phase flow predictions have been performed for the last stage of a model steam turbine to examine the influence of drag between condensed fog droplets and the continuous vapour phase. In general, droplets due to homogeneous condensation are small and thus kinematic relaxation provides only a minor contribution to the wetness losses. Different droplet size distributions have been investigated to estimate at which size inter-phase friction becomes more important. The second part of the paper deals with the deposition of fog droplets on stator blades. Results from several references are repeated to introduce the two main deposition mechanisms which are inertia and turbulent diffusion. Extensive post-processing routines have been programmed to calculate droplet deposition due to these effects for a last stage stator blade in three-dimensions. In principle the method to determine droplet deposition by turbulent diffusion equates to that of Yau and Young [1] and the advantages and disadvantages of this relatively simple method are discussed. The investigation includes the influence of different droplet sizes on droplet deposition rates and shows that for small fog droplets turbulent diffusion is the main deposition mechanism. If the droplets size is increased inertial effects become more and more important and for droplets around 1 μm inertial deposition dominates. Assuming realistic droplet sizes the overall deposition equates to about 1% to 3% of the incoming wetness for the investigated guide vane at normal operating conditions.

Experimental Investigation of Forced Response Impeller Blade Vibration in a Centrifugal Compressor With Variable Inlet Guide Vanes: Part 1—Blade Damping

2011 ◽  
Author(s):  
Armin Zemp ◽  
Reza S. Abhari ◽  
Beat Ribi
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Operating Conditions ◽  
Inlet Pressure ◽  
Dynamic Strain ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Aerodynamic Damping ◽  
Inlet Guide Vanes ◽  
Vane Angle

Forming the first part of a two-part paper, the quantification of the resonant response levels and the damping quantities for a centrifugal compressor impeller with variable inlet guide vanes under engine representative operating conditions is detailed in this work. The motivation for the investigation is the lack of experimental data that are needed to improve and validate computational tools used during the design phase. Measurements were performed during resonant blade vibrations with the inlet pressure, the inlet guide vane angle and the operating point as the varying parameters. The flow non-uniformity introduced into the inlet flow field was measured with an aerodynamic probe. These measurements showed an increase in flow distortion for increased guide vane angles. The response amplitudes were acquired with dynamic strain gauges. A curve-fit method was applied to estimate the critical damping ratios. The results showed a linear correlation of the aerodynamic damping with the inlet pressure. The mode dependent material damping was therefore derived using a linear extrapolation to vacuum conditions of the inlet pressure dependent overall damping. The resonant blade dynamics could be captured with a single degree of freedom model. The aerodynamic damping and the maximum strain response were found to significantly depend on the inlet guide vane angle setting and on the throttle setting of the compressor.

Experimental Investigation of the Upstream Effect of Different Low Pressure Turbine Exit Guide Vane Designs on Rotor Blade Vibration

2016 ◽  
Author(s):  
F. Schönleitner ◽  
T. Selic ◽  
C. Schitter ◽  
F. Heitmeir ◽  
A. Marn
Keyword(s):  
Rotor Blade ◽  
Guide Vane ◽  
Low Pressure ◽  
Operating Conditions ◽  
Numerical Code ◽  
Noise Emission ◽  
Blade Vibration ◽  
Vibration Measurements ◽  
Guide Vanes ◽  
Low Pressure Turbine

Exit guide vanes of turbine exit casings are designed to meet aerodynamic, structural and acoustic criteria. New low pressure turbine architectures of aero engines try to optimize components weight in order to decrease the fuel consumption and reduce noise emissions. For this purpose different designs of turbine exit guide vanes (TEGV) exist which vary geometry as well as the number of vanes in the casing. In the subsonic test turbine facility at the Institute for Thermal Turbomachinery and Machine Dynamics of Graz University of Technology, which represents a 1 ½ low pressure turbine stage, the upstream effect of these innovative turbine exit casings (TEC) designs is under investigation. Up to now the influence of the turbine exit casing in relation to the aerodynamic vibration excitation of the rotor blading is not well known. For rotor blade vibration measurements a telemetry system in combination with strain gauges is applied. The present paper is a report of blade vibration measurements within a rotating system in the area of low pressure turbines under engine relevant operating conditions. Within the test phase different turbine exit casings are under investigation at two different operating points (OP). These turbine exit casings represent different design goals, e.g. aerodynamically optimization was performed to reduce losses at the aero design point or an acoustically optimization was done to reduce noise emission at the operating point approach. All these different design intents lead to a changed upstream effect, thus changing rotor blade vibrations. To identify parameters affecting blade vibration attention is paid to aerodynamic measurements as well. Selected results of steady and unsteady flow field measurements are analyzed to draw conclusions. The upstream effect of different turbine exit casings can be quantified at OP1. Depending on the vane number both the potential effect of the TEGV increase and the upstream effect as well. Aerodynamic as well as acoustic improvements as wanted with H-TEC and inverse-cut-off TEC lead to unfavorable conditions and higher blade loading in comparison to the referenced TEC. OP2 provides additional information of downstream effects. Due to the stator vane number the rotor blading is excited in its 4th eigenfrequency. The comparison between all investigated turbine exit casings with respect to the referenced configuration provides a basis for numerical code validation and future developments.

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