Research on Application of Shutter Flow Regulating Valve in

Aerodynamic Performance Test of Fan

Shihui Xu

, Shuiying Zheng

, Li Li

, Rui Ma

, Jingdong Mai

and Xiaoyan Tian

China North Vehicle Research Institute, Beijing , China

Institute of Chemical Machinery Zhejiang University, Hangzhou, China

Keywords:

Aerodynamic performance test of fan, shutter flow regulating valve, united type, divided type.

Abstract: Taking DN700 shutter flow regulating valve as research object，the CFD model of vehicle cooling fan

aerodynamic performance test system is established by using Gambit and Fluent software. Through analysis

of pressure field and velocity field in duct, the application of shutter flow regulating valve in aerodynamic

performance test of fan and influence of different types of fans on performance test were discussed. The

results indicated that shutter flow regulating valves can be substituted for traditional sticking paper in

aerodynamic performance tests of fan. These make it possible to automatically control air flow of operating

state point and sample for performance test of fan. These researches provide a reference for the automation

of aerodynamic performance test for vehicle fans.

1 INTRODUCTION

C-type experimental set-up specified in GB/T

1236-2000(2001) or ISO 5801:2007 often used in

aerodynamic performance tests of cooling fan in

vehicle. During the process of these tests, people

usually stick a paste on the loading mesh of test

pipeline to load the inlet manifold of fan to adjust

flow quantity. But there are some shortcomings:

selection of test mode point is not controlled due to

stochastic of paste; there is high risk of test person

because of exposure to test environment of rotating

part in manual stick method. They can be overcome

by using shutter flow regulating valve to adjust flow

quantity, and sampling control test mode point to

realize automatic aerodynamic performance test of

fan.

Shutter Flow regulating valve often used in

wind-tunnel tests, when the diameter of pipeline is

small, it can’t be used in fan test. Because if use

shutter flow regulating valves to adjust flow quantity

in small-diameter pipeline, it will guide downstream

air flow and result in unevenness flow. And the test

will be invalid if can’t get rid of it after the air flow

passing through the rectifying gate.

Familiar shutter flow regulating valves can be

divided into united opening type and divided

opening type, see figure 1. When the valves change,

all of the blades of united opening valves will rotate

in the same direction and the blades maintain

parallel to each other, but the rotation of adjacent

blades of divided opening type is opposite. In this

paper, the shutter flow regulating valves used in

pipeline of fan test is numerically simulated(Li

Jianfeng, 2006; Chang Zezhou, 2009; Liu Song,

2009) by Fluent, include united opening type and

divided opening type, and the influence on airflow is

analyzed and contracted to confirm whether it can

be used in aerodynamic performance tests of fan or

not.

606

Xu, S., Zheng, S., Li, L., Ma, R., Mai, J. and Tian, X.

Research on Application of Shutter Flow Regulating Valve in Aerodynamic Performance Test of Fan.

In 3rd International Conference on Electromechanical Control Technology and Transportation (ICECTT 2018), pages 606-611

ISBN: 978-989-758-312-4

(a) united opening type (b) divided opening type

Fig. 1: shutter flow regulating valve

2 VA LV E A N D DUCT

MODELLING

2.1 Geometry model

Object is a pipeline that inner diameter is 700mm,

calculated model is shown in Figure 2.

Calculate area is divided into inlet section and

impeller area. Inlet section is flow field area

between pipeline inlet and fan inlet, include inlet

flatness tube segment, shutter flow regulating valve,

fairing screen and pipeline public segment, the

pressure hole on pipe wall is ignored during the

modeling. The single axial fan used have no guide

vane, parameter as follows: rim diameter 320mm,

outer diameter 690mm, width 200mm, 8 vans

uniformly distribute around, rating rev is 1750r/min.

Fig. 2: calculate area model

There are 4 vanes in a shutter flow regulating

valve, which is 175mm high and 4mm thickness.

To research the influence of united opening type

and divided opening type valves in different opening

inlet flatness tube segment

flow regulating valve

pipeline public segment

rectifier grid

tested fan

Research on Application of Shutter Flow Regulating Valve in Aerodynamic Performance Test of Fan

607

on test system flow field, 9 calculated model of

different opening are established in 10°, 20°, 30°,

40°,50°,60°,70°,80°,90°.

2.2 Mesh model

Impeller area: the edge of tetrahedron mesh is 8mm

which compartmentalize the area, and the

dimensional function is further encrypted for the

area of blade tip clearance. The number of grid cells

is about 1.2 million.

Inlet section: because the flow field near the flow

regulating valve and rectifier grid is rather complex,

it is necessary to divide the flow field with dense

mesh in order to ensure calculation higher accuracy.

The tetrahedron mesh and the hexahedron mesh with

the edge of 10 mm are used to divide the meshes

respectively. Due to its regular shape and low mesh

quality, cylindrical pipes are divided into hexahedron

grids with long edges in order to save computational

resources. The total number of grids in the whole

inlet section is about 3 million.

3 CALCULATION PROCESS

AND RESULTS

3.1 Calculation method and boundary

condition

The air is regarded as incompressible fluid, there is

no heat exchange in the flow, and the energy

conservation equation is not taken into account. The

gas is steady flow, the constant calculation is

adopted, and the influence of gravity is ignored. The

turbulent model adopts a standard k - ε model , the

near wall is applied with a standard wall function ,

and the pressure velocity is coupled with SIMPLE

algorithm , momentum equation , turbulent kinetic

energy and turbulent dissipation phase . The

convergence criterion is defined as the residual less

than 1 × 10

- 4

for all monitoring items.

The inlet boundary condition is set as the

pressure inlet , and the inlet total pressure is defined

to be zero relative to the atmospheric pressure ; the

outlet boundary condition is set to the pressure

outlet , and the outlet static pressure is defined to be

zero relative to the atmospheric pressure ; and the

solid wall adopts the non - slip boundary condition .

3.2 Analysis of CFD flow Field affected

by Valve to Air duct

3.2.1 Flux characteristics of Valve

The flux percentage of the fan varies with the

opening of the valve blade as shown in Fig. 3. It can

be seen that the flux characteristics of the united

opening valve are close to that of the fast opening

valve and the flux is bigger when the opening of the

valve is small. When the blade opening is 70 °, the

fan flux rate is close to the maximum value, and then

the flux rate just vary a little while the opening

degree increases,.

The variation of flux characteristics of divided

opening valve showed different rules, with the

increase of opening, the rate of change with flux of

the fan increased first and then decreased. When the

opening is less than 30 °, fan flow changes slowly

with the increase of opening; when the blade

opening between 30 °and 70 °, flux change from the

maximum of 20% increases to 90% rapidly with the

increase of opening fan, the rate of change with flow

is bigger than united opening valve; when the

opening increasing further, the rate of change

becomes very small, the flow characteristics now is

similar to that of united opening valve. At the same

time it can be seen that the flow of divided opening

type is always less than that of united opening type

at same opening of valve.

The flow regulating valve is installed in the

pipeline, hoping to get a linear working

characteristic, but the two kinds of valves do not

have a good linearity. The working range of the

united valve is 0 ° -70 °, and the working range of

the divided valve is 20 °-70 °.

Fig.3simulated characteristic curve of shutter flow

regulating valves

The full - pressure efficiency of the fan is shown

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608

in Fig. 4. It can be found that the two curves are

basically the same shape, especially in the small

flow area and the large flow area , this two curves

are same, which indicate the two valves can be used

to obtain the more accurate curve of the fan

performance .

Fig. 4 simulated characteristic curve of fan

The calculated flow rate of rating point of the fan

is18000m

/h, and the corresponding valve opening is

approximately 60 °, so the further analysis is carried

out with the valve blade opening of 60°.

3.2.2 Speed distribution

(a) united opening type

(b) divided opening type

Fig.5 pipeline velocity chart when valve opening is 60°

When the valve opening is 60 °, the shutter flow

regulating valve and the flow velocity near the gate

distribution are shown in Figure 5.From Figure 5

(a)we can see: when united valve blade along the

diversion effect of the gas flow through the valve

strands of the same direction deflection occurs, and

converge on top of the pipeline, resulting in velocity

of upper air significantly greater than the downside.

The average speed of upper airflow is 20.5m/s in the

pipe, and the velocity of lower pipe flow is less than

5m/s, so two blocks form a clear boundary.

At the same opening, effect of united valve on

the flow direction of deflection is much weaker.

From figure 5 (b) we can see: through the valve gap

between the blades the airflow forma high-speed jet,

these high speed jet flow along the axial direction

and converge at the head of rectifying grids. The

velocity distribution of downstream flow field is

uniform and the average speed is about 12m/s.

3.2.3 Streamline and turbulent kinetic

energy

Figure 6 and Figure 7 show the kinetic energy

distribution of streamline and turbulent near the flow

regulating valve and the rectifier grid. It can be seen

that due to the strong shear action of high-speed jet

and low-speed fluid at leeward side, fluid eddies at

the leeward side of leaves, resulting in a significant

increase in the turbulent kinetic energy.

For the united opening valve, the three vortex

areas above is intensity but range over a small field,

the bottom vortex area is weak but range over a wide

field. The mainstream converged by three jets shear

each other with low-speed fluid lower in the pipeline,

to form a larger vortex, resulting in disordered flow

between the valve and rectification grid. The

nephogram shows that the turbulent kinetic energy

lower in the pipeline is 15 times more than the lower,

at the same time we can see: the turbulent kinetic

energy decreased significantly after passing through

rectifying grid, the turbulent kinetic energy

downstream in rectifying grid is within 5m

indicating the rectifying grid can eliminate

secondary flow and combing the flow field

effectively.

The vortex area of divided opening valve is

concentrated on the rear part of the two central

blades, and the incidence is small. When the valve

downstream pass through about 1.5D, the turbulent

kinetic energy of the flow field decreases rapidly,

and the velocity distribution is very uniform at the

grid.

(a) united opening type

m/s

Research on Application of Shutter Flow Regulating Valve in Aerodynamic Performance Test of Fan

609

(b) divided opening type

Fig.6 streamline of pipeline at 60 ° opening

（a）united opening type

（b）divided opening type

Fig.7 turbulent kinetic energy nephogram of pipeline at 60 °

opening

3.2.4 Pressure distribution

Figure 8 shows the hydrostatic distribution of shutter

flow regulating valve and the flow field near the

rectifying grid. The valve blade blocks the fluid

resulting in the increased static pressure of blade

windward side, static pressure energy translate into

dynamic pressure which forming a low pressure area

due to the vortex exits in leeward side of vanes. For

the united opening valve low pressure area at the

bottom range over a wide field, in the downstream

within about 1D of the valve the pressure gradient of

pipe is obvious, and then the flow pressure

distribution tends to be uniform. The static pressure

distribution of divided opening valve is symmetrical

about the central axis, the low pressure area range

over a wide field and values small, after the low

pressure area the static pressure increase gradually,

static pressure uniformly distributed at the rectifier

grid. It can be seen that the distribution of low

pressure and vortex area is consistent.

Figure 9 and figure 10 are dynamic pressure and

static pressure nephogram of static pressure

measuring section using two kinds of valves. It can

be seen that due to the downstream flow field of

rectifying grids is flat, no matter which kind of valve

we use, static pressure distribution of static pressure

measurement section are uniform. The main

influence of the valve is the dynamic pressure, when

using the united opening valve, the dynamic pressure

measured on section is far greater than the lower side,

and this is consistent with the velocity distribution in

the pipe; when using divided opening valve, the

dynamic pressure distribution on the section is

equality. When using C type test device for fan

aerodynamic performance test, dynamic pressure of

fan is calculated by flow, gas density and

cross-sectional area rather than measurement directly,

so the uneven distribution does not affect the

dynamic pressure in fan test, but this will directly

affect the accuracy of static measurement.

(a) united opening type

（b）divided opening type

Fig.8 static pressure nephogram of pipeline at 60 ° opening

Fig.9 dynamic pressure and static pressure distribution of

static pressure measurement section (with united opening

flow regulating valve)

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610

Fig.10 dynamic pressure and static pressure distribution of

static pressure measurement section(with divided opening

flow regulating valve)

4 CONCLUSIONS

By simulating the flow characteristics of valves and

the internal flow field of united opening valve and

divided opening shutter flow regulating valves in

different opening degrees, the following conclusions

can be drawn:

1)Both valves can elicit accurate performance

curve of fan. It basically meets the requirement of

using C type test device specified in GB/T

1236-2000 or ISO 5801: 2007 in aerodynamic

performance test of fans.

2) The flow range of the fan is allowed from 8

000 m

/ h to 20 000 m

/ h, and the opening range of

the flow regulating valve is 30 °-70 °. Within this

range, the flow characteristics of the two valves is

nearly linearity, which meets the need of sampling

control of test operating conditions.

3) The deflecting effect of the united opening

valve on the airflow direction is obvious, which

leads to a big velocity gradient in the downstream

flow field, and a large scale vortex will be formed in

the downstream of the valve due to the strong shear

action of both sides of the airflow. So the flow loss is

caused and the influence range of vortex is

increasing with the decrease of opening. The

velocity distribution of downstream flow field in

divided opening valve is relatively uniform. There is

a vortex region with little influence only in the rear

of the blade. Therefore, in the point of reducing

energy loss, the divided opening valve is superior.

4)The static pressure distributions of the static

pressure measurement section of the two valves are

uniform, but the dynamic pressure distribution is

quite different. When the united opening valves

work, the aerodynamic pressure above the cross

section is much larger than that on the lower side,

which is consistent with the velocity distribution in

the pipeline. The dynamic pressure distribution on

the cross section is uniform when adopting the

divided opening valve. The uniformity of the

dynamic pressure distribution will affect the

accuracy of the static pressure measurement directly.

Therefore, divided opening valve is superior

considered measurement accuracy.

In summary, when using C type test device

specified in GB/T 1236-2000 or ISO 5801: 2007 in

fan aerodynamic performance tests, the inlet duct

can be loaded by the divided opening shutter flow

regulating valve instead of the manual sticker

method in order to realize the sampling control of

mode point and test automation.

ACKNOWLEDGEMENTS

Authors would like to acknowledge National key

research and development plan of China (Grant No.

2016YFC0801204)

REFERENCES

GB/T 1236-2000 Industrial fans - Performance testing

using standardized airways[S]. Beijing：Standards

Press of China，2001.

ISO 5801:2007 Industrial fans——Performance testing

using standardized airways

Li Jianfeng，LV Jun-fu. Simulation of Air Flow in a

Blower[J]. Fluid Machinery，2006，34(4):11-13.

Chang Zezhou，LuoHao. Application of CFD Software in

the Design of Fan[J]. Compressor, Blower and Fan

Technology，2009(2)，60-64.

Liu Song，Wu Shufu，Zhang Lixiang. Discussion of 3-D

Modeling for Axial-flow Fan and Its Internal Flow

Field Based on CFD[J]. Compressor, Blower and Fan

Technology，2009(2)，16-19.

Pa Pa

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