Influence of Freely Rotating Inlet Guide Vanes on the Return Flows and Stable Operating Range of an Axial Flow Fan

1980 ◽  
Vol 102 (1) ◽  
pp. 75-80 ◽  
Author(s):  
N. Venkatrayulu ◽  
D. Prithvi Raj ◽  
R. G. Narayanamurthi
Keyword(s):  
Guide Vane ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Axial Distance ◽  
Axial Flow Fan ◽  
Guide Vanes ◽  
Operating Range ◽  
Inlet Guide Vanes ◽  
Stable Operating ◽  
Return Flows

This paper presents the results of experimental investigations on the three-dimensional flow and performance characteristics of a free vortex axial flow fan rotor, with a freely rotating and braked inlet guide vane row. The influences of axial distance between the inlet guide vane row and the rotor inlet, inlet guide vane setting angle and shape, partial omission of guide vanes at the hub and tip regions on the return flows have been studied and optimum axial distance and setting angle that will improve the useful operating range of the fan were determined. Use of freely rotating inlet guide vanes at high flow volumes and braked inlet guide vanes at low flow coefficients resulted in a reduction of return flows and an increase of the stable operating range of the axial fan rotor by more than 35 percent and this combination has yielded higher efficiencies as well in the extended region of stable operation.

The Effects of Variable-Inlet Guide Vanes on Performance of an Axial Flow Pump With Tip Clearance

2015 ◽  
Author(s):  
Wei-Min Feng ◽  
Jing-Ye Pan ◽  
Zhi-Wei Guo ◽  
Qian Cheng
Keyword(s):  
Reverse Flow ◽  
Guide Vane ◽  
Axial Flow ◽  
Tip Clearance ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Pump Head ◽  
Axial Flow Pump ◽  
Flow Pump

The effects of variable-inlet guide vanes on the performance of an axial flow pump considering tip clearance are investigated. The performance and the main flow field of the whole passage with five different angles of inlet guide vanes ( −10°, −5°, 0°, 5°, 10°) and with two tip clearance sizes (1‰ and 2‰) are presented. The results show that when the angle of inlet guide vane increases from negative values to positive values, the pump head reduces for two tip clearance sizes. This is mainly caused by the change of inlet velocity triangle of blade. Moreover, as tip clearance size increases from 1‰ to 2‰, both the pump head and efficiency decrease because of increasing of the strength of tip clearance leakage vortex and reverse flow.

The Effect of the Thickness and Angle of the Inlet and Outlet Guide Vane on the Performance of Axial-Flow Pump

2016 ◽  
Author(s):  
Sang-Won Kim ◽  
Youn-Jea Kim
Keyword(s):  
Numerical Analysis ◽  
Numerical Study ◽  
Guide Vane ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Pump Performance ◽  
Blade Thickness ◽  
Axial Flow Pump ◽  
Flow Pump

An axial-flow pump has a relatively high discharge flow rate and specific speed at a relatively low head and it consists of an inlet guide vane, impeller, and outlet guide vane. The interaction of the flow through the inlet guide vane, impeller, and outlet guide vane of the axial-flow pump has a significant effect on its performance. Of those components, the guide vanes especially can improve the head and efficiency of the pump by transforming the kinetic energy of the rotating flow, which has a tangential velocity component, into pressure energy. Accordingly, the geometric configurations of the guide vanes such as blade thickness and angle are crucial design factors for determining the performance of the axial-flow pump. As the reliability of Computational Fluid Dynamics (CFD) has been elevated together with the advance in computer technology, numerical analysis using CFD has recently become an alternative to empirical experiment due to its high reliability to measure the flow field. Thus, in this study, 1,200mm axial-flow pump having an inlet guide vane and impeller with 4 blades and an outlet guide vane with 6 blades was numerically investigated. Numerical study was conducted using the commercial CFD code, ANSYS CFX ver. 16.1, in order to elucidate the effect of the thickness and angle of the guide vanes on the performance of 1,200mm axial-flow pump. The stage condition, which averages the fluxes between interfaces and is accordingly appropriate for the evaluation of pump performance, was adopted as the interface condition between the guide vanes and the impeller. The rotational periodicity condition was used in order to enable a simplified geometry to be used since the guide vanes feature multiple identical regions. The shear stress transport (SST) k-ω model, predicting the turbulence within the flow in good agreement, was also employed in the CFD calculation. With regard to the numerical simulation results, the characteristics of the pressure distribution were discussed in detail. The pump performance, which will determine how well an axial-flow pump will work in terms of its efficiency and head, was also discussed in detail, leading to the conclusion on the optimal blade thickness and angle for the improvement of the performance. In addition, the total pressure loss coefficient was considered in order to investigate the loss within the flow paths depending on the thickness and angle variations. The results presented in this study may give guidelines to the numerical analysis of the axial-flow pump and the investigation of the performance for further optimal design of the axial-flow pump.

Ice Crystal Icing Investigation on a Honeywell Uncertified Research Engine in an Altitude Simulation Icing Facility

2020 ◽  
Author(s):  
Ashlie B. Flegel
Keyword(s):  
Particle Size ◽  
Guide Vane ◽  
Leading Edge ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Ice Crystal ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
The Core ◽  
Break Up

Abstract A Honeywell Uncertified Research Engine was exposed to various ice crystal conditions in the NASA Glenn Propulsion Systems Laboratory. Simulations using NASA’s 1D Icing Risk Analysis tool were used to determine potential inlet conditions that could lead to ice crystal accretion along the inlet of the core flowpath and into the high pressure compressor. These conditions were simulated in the facility to develop baseline conditions. Parameters were then varied to move or change accretion characteristics. Data were acquired at altitudes varying from 5 kft to 45 kft, at nominal ice particle Median Volumetric Diameters from 20 μm to 100 μm, and total water contents of 1 g/m3 to 12 g/m3. Engine and flight parameters such as fan speed, Mach number, and inlet temperature were also varied. The engine was instrumented with total temperature and pressure probes. Static pressure taps were installed at the leading edge of the fan stator, front frame hub, the shroud of the inlet guide vane, and first two rotors. Metal temperatures were acquired for the inlet guide vane and vane stators 1–2. In-situ measurements of the particle size distribution were acquired three meters upstream of the engine forward fan flange and one meter downstream of the fan in the bypass in order to study particle break-up behavior. Cameras were installed in the engine to capture ice accretions at the leading edge of the fan stator, splitter lip, and inlet guide vane. Additional measurements acquired but not discussed in this paper include: high speed pressure transducers installed at the trailing edge of the first stage rotor and light extinction probes used to acquire particle concentrations at the fan exit stator plane and at the inlet to the core and bypass. The goal of this study was to understand the key parameters of accretion, acquire particle break-up data aft of the fan, and generate a unique icing dataset for model and tool development. The work described in this paper focuses on the effect of particle break-up. It was found that there was significant particle break-up downstream of the fan in the bypass, especially with larger initial particle sizes. The metal temperatures on the inlet guide vanes and stators show a temperature increase with increasing particle size. Accretion behavior observed was very similar at the fan stator and splitter lip across all test cases. However at the inlet guide vanes, the accretion decreased with increasing particle size.

Numerical Study of Variable Camber Inlet Guide Vane on Low Speed Axial Compressor

2015 ◽  
Author(s):  
Emandi Rajesh ◽  
Bhaskar Roy
Keyword(s):  
High Efficiency ◽  
Numerical Study ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Operating Range ◽  
Clockwise Direction ◽  
High Diffusion ◽  
Stable Operating ◽  
Stagger Angle

The modern engine has the requirement of high pressure ratio compressors. High diffusion blades are used to cater to this requirement. The high diffusion blades suffer from the low incidence range. A variable geometry inlet guide vane is used to improve the incidence range and to have an increased stable operating range. In this paper a variable camber inlet guide is proposed in place of an existing inlet guide vane (IGV) to operate the compressor at increased stable operating range or to operate at improved efficiency at off design point. Numerical analysis is carried out in ANSYS CFX©. The existing compressor consists of IGV (20 blades) , rotor (43 blades) and stator (52 blades). The rotor rotates at 2400 rpm in clockwise direction. The IGV blade is split two part forward blade and aft blade. Numerical studies are conducted to study the effect of varying the stagger angle on the performance of the compressor. The aft blade is given rotation in clockwise direction for +5° and +10°. The numerical results obtained are compared to the same stagger angle with full blades. It is observed that marginal improvement in the pressure ratio and efficiency. 7% stall margin improvement is achieved with slotted blade in place a fixed IGV at 0° setting angle. A new compressor characteristics is estimated which shows that the compressor can be operated to the left of the fixed-IGV-stage peak pressure with high efficiency.

Effect of inlet guide vanes on the performance of small axial flow fan

2017 ◽  
Vol 26 (6) ◽  
pp. 504-513 ◽  
Author(s):  
Yang Liu ◽  
Zhe Lin ◽  
Peifeng Lin ◽  
Yingzi Jin ◽  
Toshiaki Setoguchi ◽  
...  
Keyword(s):  
Axial Flow ◽  
Axial Flow Fan ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Small Axial Flow Fan

Pressure Fluctuations Due to Interaction between Blade Rows in Axial Flow Compressors

1968 ◽  
Vol 183 (1) ◽  
pp. 153-164 ◽  
Author(s):  
R. Parker
Keyword(s):  
Guide Vane ◽  
Pressure Fluctuations ◽  
Axial Flow ◽  
Rotor Blades ◽  
Inlet Guide Vane ◽  
Pressure Amplitude ◽  
Guide Vanes ◽  
Large Pressure ◽  
Flow Compressor ◽  
Alternative Designs

The paper presents the results of a theoretical and experimental investigation into the potential flow interaction effects between blade rows in an axial flow compressor stage. The investigation is concentrated on the inlet guide vane/rotor interaction and shows that the passing of the rotor blades behind the guide vanes produces large pressure fluctuations on the surfaces of the guide vanes. The available method of computation is not yet adequate for prediction of absolute values of pressure amplitude but does provide a sound basis for comparison between alternative designs.

Inlet Guide Vane Performance of Centrifugal Blowers

1961 ◽  
Vol 83 (4) ◽  
pp. 371-378
Author(s):  
A. J. Stepanoff
Keyword(s):  
Centrifugal Pump ◽  
Guide Vane ◽  
Power Reduction ◽  
Single Stage ◽  
Experimental Results ◽  
Inlet Guide Vane ◽  
Pump Field ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Specific Speed

The function and effectiveness of the inlet guide vanes to control the blower output and power requirements are examined. Calculated and experimental results of the power reduction by means of guide vanes are presented. The concept of the “Inlet Specific Speed” widely used in centrifugal pump field is discussed in application to the blowers. A method of estimating the performance of single-stage blowers for any position of the guide vanes is suggested. A “casing characteristic” is introduced for this purpose and its utility for the calculation of the impeller diameter for a reduction of the output is demonstrated. The performance of the inlet vanes of multistage blowers is reviewed.

Experimental and numerical analysis of the unsteady influence of the inlet guide vanes on cavitation performance of an axial pump

2018 ◽  
Vol 233 (11) ◽  
pp. 3816-3826 ◽  
Author(s):  
Zhiwei Guo ◽  
Jingye Pan ◽  
Zhongdong Qian ◽  
Bin Ji
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Cavitation Performance ◽  
Axial Pump ◽  
Simulation Results

The effect of the inlet guide vanes on cavitation performance of an axial pump is investigated to assess the mechanism for cavitation in pumps and improve their cavitation performance. The effect of inlet guide vane angles on cavitation performance was assessed experimentally, and computational fluid dynamics was used to analyze the inner flow field of the axial pump and to probe the cavitation mechanism. The simulation results agree qualitatively with the experimental data, showing that cavitation performance is improved with positive inlet guide vane angles but hampered with negative ones. The cavitation performance itself is controlled by the cavitation volume, which first expands circumferentially when the net positive suction head decreases from a certain large value and then develops toward the axis radially after the net positive suction head reaches a certain value. This is when the cavitation performance deteriorates. Comparing cavitation volume for the critical net positive suction head as determined by two different methods, the method based on efficiency drop (NPSHeff.,1%) is found to be more suitable than that based on head drop (NPSHhead.,3%). Furthermore, the distribution of swirl is shown to be closely related to the distribution of cavitation, a feature that may be used to predict cavitation along the impeller.

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.

Design of a Free Turbine for Simulation of Flow in a Turbine-Annular-Diffuser-With-Struts Delivery System

2009 ◽  
Author(s):  
Srinuvasu Dakuri ◽  
Bhaskar Roy
Keyword(s):  
Guide Vane ◽  
Air Flow ◽  
Inlet Guide Vane ◽  
Design Intent ◽  
Flow Angle ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Annular Diffuser ◽  
The Absolute ◽  
Turbine Design

A free turbine is intended to produce the effect of a rotating flow field to be fed into a strutted annular diffuser for simulating a 3D fluid mechanic interaction and effect. This turbine is driven by the flow from a flow driver fan, upstream of the turbine. As sufficient pressure is required for the diffuser air flow, the concept of maximum work generation by a turbine is bypassed in the design intent. An inlet guide vane is designed for the turbine such that the rotational speed of the turbine matches the design intended speed and also produces an axial exit flow (no swirl) at design condition, and a rotating wake for off design conditions. The consideration of using of the inlet guide vanes (rather than usual stator-nozzles) is to avoid a mismatch between the absolute angle of the flow coming from the flow driver fan and the absolute design intent flow angle requirement, to run the turbine. Also, due to the 3D flow effects, some uncertainty exists in determining the exact entry air flow angle to the guide vane; this uncertainty is provided for with a rounded leading edge to the inlet guide vanes. The above design considerations when embedded in the conventional turbine design procedure resulted in an unusual turbine design with very low blade cambers.

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