RESEARCH ARTICLE

Experimental investigation into wing span and angle-of-attackeffects on sub-scale race car wing/wheel interaction aerodynamics

S. Diasinos A. Gatto

Received: 29 October 2007 / Revised: 9 March 2008 / Accepted: 22 March 2008 / Published online: 13 April 2008

Springer-Verlag 2008

Abstract This paper details a quantitative 3D investiga-

tion using LDA into the interaction aerodynamics on a sub-

scale open wheel race car inverted front wing and wheel.

Of primary importance to this study was the influence of

changing wing angle of attack and span on the resulting

near-field and far-field flow characteristics. Results

obtained showed that both variables do have a significant

influence on the resultant flow-field, particularly on wing

vortex and wheel wake development and propagation.

1 Introduction

Current open wheel race car performance depends heavily

on the effectiveness and efficiency of its aerodynamics.

Appendages such as inverted wings, diffusers, barge boards

and splitter plates are currently used to enhance perfor-

mance, but the physics and mechanisms through which this

is achieved, particularly via various component interac-

tions, remains poorly understood. From a design

perspective, the ultimate goal of the designer is to con-

tribute to the downforce produced by a race car while

minimizing drag. This enhances the mechanical grip of the

tires on the track, allowing the vehicle to corner at speeds

which would otherwise be impossible. On modern open

wheeled race cars, approximately 30% of the total down-

force produced originates from the front wing (Metz 1987;

Dominy 1992). However, the close proximity of the front

wheels to the front wing can have a significant influence on

this performance metric (Katz 2006; Agathangelou and

Gascoyne 1998).

Surprisingly, very little information relating to open

wheel/inverted wing interaction exists in the open source

literature. This is most probably due to the sensitive nature

of this information in the extremely competitive and lucra-

tive businesses at the pinnacle of motor racing, particularly

Formula 1. There are however, an ever increasing number of

investigations appearing in the literature concerned specif-

ically with investigating an inverted wing or wheel in

isolation (Zerihan and Zhang 2000; Katz 1986; McManus

and Zhang 2006). Two such investigations for the isolated

wing case were conducted recently by Zerihan and Zhang

(2000) and Ranzenbach and Barlow (1996). Independently,

they both found that a downforce loss phenomenon can

occur with a small, subsequent reduction beyond a critical

ride height. This was later found to be fundamentally caused

by the development of severe adverse pressure gradients on

the wing undersurface as the ride height was reduced. Ze-

rihan and Zhang (2003) followed up this work with an

additional 3D experimental analysis, using LDA, to deter-

mine the effect of varying ride height and front wing angle

of attack (AOA) on the overall wake structure, together with

the formation and displacement of tip vortices. Results from

this analysis showed that as the wing approached the

ground, the region of separated flow and the size of the wake

increased, moving towards the ground plane as it travelled

downstream. With subsequent further reductions in ride

height, the vortex strength was found to increase up until a

critical ride height at which a loss of downforce, and con-

sequently wing tip vortex strength, occurred.

S. Diasinos

Toyota F1, Koln, Germany

e-mail: s.diasinos@unsw.edu.au

A. Gatto (&)Department of Mechanical Engineering,

School of Engineering and Design,

Brunel University, UB8 3PH Uxbridge, England

e-mail: alvin.gatto@brunel.ac.uk

123

Exp Fluids (2008) 45:537546

DOI 10.1007/s00348-008-0499-z

As one of the first investigations to consider the realistic

flow conditions over an isolated rotating wheel, Fackell and

Harvey (1975) published both qualitative and quantitative

experimental results using a moving ground at a Reynolds

Number (based on wheel diameter) of 5.3 9 105. In this

work, it was demonstrated that spinning the wheel and

having it in contact with the ground is of vital importance

to obtain appropriate lift and drag values. In previous

studies this was not, necessarily, considered critical

(Stapleford and Carr 1970). Perhaps, the most striking of

the results presented by Fackrell (1974) was the detection

of surface pressure coefficients greater than two in the

upstream region of the contact patch (i.e the cross-sectional

area of the wheel in contact with the ground) due primarily

to the effects of viscous jetting (Fackrell 1974). This jetting

effect was found to be a bi-product of the interaction

between the oncoming airstream and the wheel/road junc-

ture, producing an effective and significant pumping of

the air out into the freestream from either side of the wheel.

Considering the specific case of a front wing and wheel

operating in close proximity, Thisse (2004) conducted a

small number of computational investigations using Flu-

ent on differing endplate designs with the front wheelincluded. The analysis was compiled at fixed wing span,

chord, ride height, and AOA with results obtained indi-

cating as much as a 36% reduction of wing downforce

with the wheel present over the isolated wing case. This

was thought to be due to lower wing surface exposure to

the high pressure region formed forward of the wheel

contact patch. Curiously, results also showed that the flow

separation position on the wheel occurred aft of the

position of maximum wheel height with the wing instal-

led. Mortel (2003) and Cumming (2002) also presented

results for the wing/wheel interaction case with the former

investigating improved endplate designs and the later, the

effect of wing sweep. Unfortunately, neither offered any

great insight into the aerodynamic interaction of a wing

and wheel, but they did indicate that the inclusion of the

wheel made the flow over the wing significantly more

three-dimensional.

2 Experimental setup and apparatus

2.1 Inverted wing and wheel geometry

For all experimental investigations, the wing comprised a

single element, constant chord (c = 0.075 m), NACA 4412

aerofoil profile. A rectangular endplate with a rounded

leading edge and a tapered trailing edge was fitted at the

wing tip. For all AOA conditions considered, the base of

the endplate was fixed at a position 0.04c below the lowest

vertical position of the wing surface. The lowest vertical

position of the wing surface was also used as a reference

for ride height which was defined as the distance from this

position to the ground plane. For this investigation, ride

height was fixed at h = 0.13 c. The overall wheel diameter

and width were 1.17 and 0.631 c, respectively, with both

wheel edges incorporating shoulder radii of 0.067 c to

more accurately depict a real tire cross-section. The mini-

mum distance between the endplate and the front of the

wheel was maintained at 0.087 c for all cases investigated,

with the wing span adjustable from O = 0100% overlap

of the wheel width. The range of AOA investigated was

from 0 to 12 with increments of 4. A picture of the setupused is shown in Fig. 1.

2.2 Experimental setup

All experimental results were obtained using a 225 mm by

340 mm open circuit, closed test section, wind tunnel. A

moving ground was also built and installed in the wind

tunnel with a belt span of 200 mm (93% of the tunnel

width) and an overall length of 990 mm. A purpose built

duct, located upstream of the belt (Fig. 2a), was used to

remove the boundary layer formed over the tunnel floor to

accurately simulate moving model conditions. An example

of the velocity profile at a location -2 c upstream of the

model station, under operating conditions without the

model installed, is shown in Fig. 3. The nominal freestream

turbulence level in the wind tunnel was measured at 0.15%,

with all experiments conducted at a freestream velocity

(Vo) of 10 ms-1 0.05 ms-1. This gave a test Reynolds

number, based on wing chord, of 5.11 9 104.

The wing, wheel, and endplate used for all experimental

testing was manufactured from polished acrylic to ensure a

smooth, transparent surface (Fig. 1). The wheel was

mounted in position via a faired sting connected to the test

section wall and incorporated deep groove ball bearings to

allow free rotation from contact with the moving ground

Fig. 1 Inverted wing and wheel setup

538 Exp Fluids (2008) 45:537546

123

belt. The scale of the experimental wind tunnel model was

approximately 1:7.5.

The support system for the wing/endplate combination

allowed an AOA adjustment resolution of 0.05, with thespan of the wing, wheel track, ride height of the endplate,

and distance between the endplate and the wheel all posi-

tioned to better than 0.1 mm. Under experimental test

conditions, the belt of the moving ground, at no stage, was

observed to lift up and was operated at 10 ms-1 0.2 ms-1.

The maximum test section blockage for the wing/wheel

combination was calculated at 9.5%. At this level, it is

envisaged that blockage effects will cause a certain degree

of flow constrainment (i.e reduced vortex expansion and

artifical delay of flow separation) on the flowfield. It should

be noted, however, that the main focus of this work is

considered comparative, thereby reducing somewhat the

significance of blockage effects on the overall trends and

correlated results.

To obtain all experimental data, LDA surveys were

performed over four planes located, between, and aft of the

wing and wheel combination. As indicated in Fig. 2b, the

location of these planes were referenced to the wheel center

plane and staggered at x = -0.63 c, x = 0.75 c, x =

1.50 c, and x = 3.00 c, respectively. All LDA results were

taken in an area of interest 1.63 c high by 2.1 c wide ref-

erenced 2 mm from the left test section wall (Fig. 1) and

Fig. 2 a Overall layout of testrig, b LDA measurement planes

Exp Fluids (2008) 45:537546 539

123

1 mm off the belt surface. LDA measurements within these

planes, were taken at approximately 400 points within

these boundaries, with measurement points selected to be

more densely packed in close proximity to the wing and

wheel. For the plane located at x = -0.63 c, access of the

LDA beams was inhibited by the model, allowing there-

fore, only partial data collection at this measurement

station.

The 3D Dantec LDA system used to measure all

velocities comprised a 5 W ArIon laser and was config-

ured to operate in coincident, backscatter mode. The LDA

probes were mounted on a computer controlled traverse

which was adjustable to within 0.01 mm over identical

translation ranges in the X, Y, and Z directions of

1,010 mm. Procedures outlined by Benedict and Gould

(1996) were used to estimate the 95% confidence interval

for the LDA results with the accuracy of non-dimensional

velocity magnitude found to be better than 0.03. A single,

Laskin type atomizer, using vegetable oil to generate

seeding particles, was incorporated into the test setup to

seed the flow and obtain all velocity data. At each mea-

surement point analyzed, within each measurement plane,

the final value for the three components of velocity

obtained was acquired from averaging more than 2,000

instantaneous samples.

3 Results and discussion

3.1 Wheel without wing, comparison of stationary

and rotating wheel

Results obtained from the rotating and stationary isolated

wheel cases are presented in Fig. 4. As with all following

results, to aid in both qualitative and quantitative analy-

ses, both constant non-dimensional streamwise velocity

iso-contours (Vx/Vo) as well as the in-plane flow direction

and relative magnitude (arrows indicate Vyz) are presented.

On first inspection, the two main wheel vortex structures

found in previous investigations are clearly evident in all

but the foremost measurement plane (Fackrell 1974; Axon

1998). These vortices are setup in the recirculation zone

behind the wheel from flow entrained from the freestream

(McManus and Zhang 2006; Zhang et al. 2006). Clearly

visible also at the measurement plane X = -0.63, is a

stagnation region located at approximately mid-height for

both wheel configurations. Flow physics dictate that flow

stagnation also occur at the junction of the wheel/road

interface (i.e the contact patch), however the proximity of

the measurement plane to this region gives very little

indication of its existence. The high pressure region gen-

erated at this location is known to accelerate and eject the

flow cross-stream, where a complex interaction with the

freestream occurs around the wheel edge (McManus and

Zhang 2006).

Considering more closely the development of the wheel

vortices, from Fig. 4ch, the general trend is for the vortex

size and separation distance to increase with further

propagation downstream. The wheel vortex separation

distance is particularly evident when comparing Fig. 4c

(0.9 \ Y \ 1.55) to Fig. 4g (0.75 \ Y \ 1.9) and Fig. 4d(0.85 \ Y \ 1.65) to Fig. 4h (0.5 \ Y \ 1.9). Theseresults show that through rotating the wheel, decreases in

wheel vortex separation distance by up to 20% (at X = 3)

can be achieved over the stataionry wheel configuration.

Also clear from comparing Fig. 4c, e to d, f is that the

general wheel vortex shape appears significantly flatter

in the non-rotating case than that observed for the rotating

configuration. This result has been inferred by past publi-

cations (Fackell and Harvey 1975; McManus and Zhang

2006) and is thought to result from the differing amounts of

the viscous jetting flow and the different flow separation

positions between the two configurations.

Further comparisons between the rotating and stationary

cases in Fig. 4 also show subtle differences in the complex

near wake structure directly behind the wheel (Fig. 4c, d).

First, the results indicate that the wheel wake for the rotating

case is thinner and marginally higher (0.95 \ Y \ 1.6,Z = 1.5) than that found for the stationary configuration

(0.8 \ Y \ 1.65, Z = 1.4), indicating delayed separationover the top of the wheel. This finding is further supported by

differences found in the degree of flow entrainment down the

centre of the rear of the wheel at this measurement location.

From direct comparison of the in-plane velocity results

between the two cases, velocity magnitudes of up to 10%

greater where found for the stationary case. Supplimental to

this result is that this increased degree of flow entraiment is

seen to extend closer to the ground plane for this case

(indicated in Fig. 4d). In previous work, (Fackell and Harvey

Fig. 3 Velocity profile -2 c upstream of wheel centreline; emptytest section, mid-span

540 Exp Fluids (2008) 45:537546

123

1975; McManus and Zhang 2006), this increased entrain-

ment for the stationary case was found to be due to the

decelerating flow on the rear surface of the wheel being

energized by the entrained main streamwise flow around the

sides. This promotes the central region of attached flow as it

is directed down the rear face of the wheel and toward the

ground. Additionally, this characteristic of flowfield, and

the subsequent bi-furcation of the flow as proximity to the

ground increases, clearly implies the existence of a down-

stream stagnation line on the ground plane (Fig. 4f).

Fig. 4 Comparison ofstationary and rotating isolated

wheel results

Exp Fluids (2008) 45:537546 541

123

3.2 Wheel and wing, wing span 100%

From Figs. 5 and 6, it is immediately apparent that the flow

characteristics have become much more complex with the

addition of the front wing at full span (silhouette indicated).

This is particularly the case in the flowfield directly behind

and around the wheel boundaries. In this region, the overall

flowfield is clearly more asymmetric with an additional

primary wing vortex clearly visible at the wingtip (i.e

Fig. 5g at Y = 1.4, Z = 0.15). This vortex is generated via a

pressure differential setup around the wing tip/endplate

structure through wing undersurface suction (Zerihan and

Zhang 2003). This vortex rotates in an anti-clockwise

direction and when comparing Fig. 5e, g, as expected,

clearly becomes larger with increasing angle of attack.

Together with these characteristics, increasing wing angle

of attack also produces more significant crossflow across

the wheel face as can be most vividly shown when com-

paring Fig. 5a, g. For these two particular cases, a change in

angle of attack of 12 has increased the local in-plane non-dimensional velocity magnitude Vyz/Vo, from essentially

zero at Y = 1.25, Z & 0 to Vyz/Vo = 0.4. As the angle ofattack is reduced however, the ability of this vortex to

promote crossflow velocity and overcome the high pressure

region within the contact patch clearly diminishes with

Vyz/Vo at Y = 1.25, Z & 0 for AOA = 4 and 8 beingVyz/Vo & 0 and Vyz/Vo = 0.1, respectively. The primaryvortex, under these conditions, would posses an enhanced

ability to move around the outside of the wheel rather than

along the front face, and finally, on its inside.

Further to the previous discussion, increasing the AOA

of the wing up to 12 is seen to fundamentally shift theaerodynamics in the vicinity of the contact patch. At these

extreme conditions, the enhanced crossflow generated

creates conditions where the initially symmetric viscous

jetting (Fig. 4a, c) becomes highly asymmetric (Fig. 5ch).

The primary effect of this resulting asymmetry is seen both

at this measurement station (X = 0.75) as well as further

downstream. From comparing Figs. 6 to 4, a significantly

increased degree of wake asymmetry is also clearly evi-

dent. The resultant wake, with the wing installed, leads to a

general bias toward the inside of the wheel, entraining the

flow to this side, and ultimately setting up the predominant,

final anti-clockwise flow rotation condition as shown in

Fig. 6b, d, f, h. In Fig. 6b, d, f, h, the flowfield has become

much less distinct to individual flow characteristics,

effectively being now, only a mixture of the more specific

flow features shown upstream.

Another interesting aspect of note with the addition of

the front wing is the movement of the stagnation position at

mid-wheel height as angle of attack is increased. From an

AOA = 012, the height of the stagnation position wasfound to move from Z = 0.5 to Z = 0.55. Adjacent to this

region, at mid-wheel height, evidence also exists for a

substantial degree of flow acceleration (Vyz/Vo = 0.70.9)

over the top of the endplate and into the mainstream flow

along the outside of the wheel (Fig. 5a, c, e, g). This flow

characteristic, which intensifies with AOA increase, is also

prominent when the AOA = 0o (Fig. 5a), which would be

expected due to the proximity of the stagnation region at

mid-wheel height.

On further comparison of results from Figs. 4 and 5, the

wake behind the wheel with the addition of the front wing

was also found to be significantly more compact than that

shown for the isolated wheel case (both stationary and

rotating) shown in Fig. 4. Additionally, the wake height

with the addition of the front wing seems to have reduced

slightly to approximately the top of the wheel between

1.2 \ Z \ 1.3 (Fig. 5b, d, f, h) when compared to bothwheel alone cases (1.4 \ Z \ 1.5). In this instance, thewing clearly assists the flow in overcoming the obstacle of

the wheel thereby tending to reduce the likelihood of pre-

mature flow separation over the top of the wheel and the

subsequent higher wheel wake. As can be seen in Fig. 5b, d,

f, h, this decrease in wake height with the wing installed was

also found to reduce the flow velocity entrained to the floor

by upwards of 30% compared to the isolated wheel cases.

3.3 Wheel and wing, wing span 0%

Results for the wing/wheel combination as the front wing

angle of attack is increased for the minimum span condi-

tion are shown in Fig. 7. At first inspection, there exists a

much larger vortex located at Y = 0.5, Z = 0.2 (Fig. 7c)

which travels on the inside of the wheel and towards the

wind tunnel wall (symmetry plane). This larger vortex,

which is now augmented by the high pressure region of the

contact patch, is also shown to translate vertically upwards

from Z = 0.2 to Z = 0.3 (Fig. 7d) with change in wing

AOA. This result was thought to be due mainly to the

added contribution of flow upwash with increase in wing

AOA. Additionally, as can be seen from Fig. 7eh, this

flow feature also remains one of the dominant flow features

for both angles of attack, and together with the left wheel

vortex, produces a general clock-wise rotation on the

overall downstream wake field (Fig. 7g, h). This final result

is in direct opposition to the result found at the same

measurement locations for the full span condition shown in

Figs. 5 and 6.

Another interesting contrast with the results presented

for the longest wing span tested, is that for the shortest

wing span configuration, for the largest angle of attack,

there is a clear absence of any dominant crossflow within

the contact patch region (Figs. 5g, 7b). Additionally, the

mid-wheel height stagnation position remains relatively

unaffected with AOA change at this decreased wing span

542 Exp Fluids (2008) 45:537546

123

condition. However, the acceleration of the flow over the

end plate clearly remains, albeit, now moving inboard

instead of outboard as described in Sect. 2. Interestingly,

for the short wing span, the maximum in-plane velocity

magnitude within this region was found to be measurably

smaller with Vyz/Vo = 0.8 at AOA = 12 compared toVyz/Vo = 0.9 found in Fig. 5. Under these conditions, the

high pressure regions at both the mid-height of the wheel

and on the upper wing surface now tend to react against

each other, leading to lower flow velocities.

4 Conclusion

An investigation into the effect of changing wing span and

angle of attack on the interaction aerodynamics of a sub-

Fig. 5 Comparison of resultsfor maximum wing span;

X = -0.63 and X = 0.75

Exp Fluids (2008) 45:537546 543

123

scale inverted wing and wheel, in ground effect, is pre-

sented. Experimental results obtained using 3D LDA are

presented and were used to show various component

interaction aerodynamic phenomenon in an attempt to

broaden understanding of this complex interaction. It was

demonstrated that when the wing span is adjusted across

Fig. 6 Comparison of resultsfor maximum wing span;

X = 1.5 and X = 3

544 Exp Fluids (2008) 45:537546

123

Fig. 7 Comparison of resultsfor minimum wing span

Exp Fluids (2008) 45:537546 545

123

the width of a wheel at different AOA, the primary wing

vortex plays a significant role in the resulting flow physics.

Primarily, at low wing spans the primary wing vortex

travels on the inside of the wheel producing a complex

asymmetric wake structure with general rotational char-

acteristics in the clockwise direction when viewed from in

front of the combination. At larger spans the reverse was

found. The primary mechanism for changing wing AOA

was to change the size, strength and degree of movement of

the tip vortex generated from the main wing element. It is

hoped that while the conditions specified in this paper are

specific and sub-scale, there are clearly defined trends and

characteristics in the results presented that may give the

designer an initial, useful, and macroscopic insight into this

highly complex flow phenomenon.

References

Agathangelou B, Gascoyne M (1998) Aerodynamic considerations of

a formula 1 racing car. Society of automotive engineers (980399)

Axon L (1998) The aerodynamic characteristics of automobile

wheels-cfd prediction and wind tunnel experiment. Ph.D.

dissertation, College of Aeronautics, Cranfield University

Benedict L, Gould RD (1996) Towards better uncertainty estimates

for turbulence statistics. Exp Fluids 22(2):129136

Cummings R (2002) Cfd investigation of front wing geometry of a

formula 3 car. M.Sc., Cranfield College of Aeronautics, Cran-

field University

Dominy RG (1992) Aerodynamics of grand prix cars. In: Proceedings

of the institution of mechanical engineers, Part D. J Automob

Eng 206(D4):267274

Fackell JF, Harvey JK (1975) The aerodynamics of an isolated road

wheel. AIAA proceedings of the second symposium on aerody-

namics of sports and competition automobiles

Fackrell JE (1974) The aerodynamics of an isolated wheel in contact

with the ground. Ph.D. dissertation, Faculty of Engineering,

University of London

Katz J (1986) Aerodynamic model for wing-generated downforce on

open-wheel-racing-car confiurations. Society of automotive

engineers (860218)

Katz J (2006) Aerodynamics of race cars. Annu Rev Fluid Mech

36:2763

McManus J, Zhang X (2006) A computational study of the flow

around an isolated wheel in contact with the ground. J Fluids Eng

128(3):520530

Metz LD (1987) Aerodynamic properties of indy cars. Society of

Automotive engineers (870726)

Mortel F (2003) The front wing. M.Sc., Cranfield College of

Aeronautics, Cranfield University

Ranzenbach R, Barlow J (1996) Cambered airfoil in ground effect

an experimental and computational study. Society of Automotive

engineers (960909)

Stapleford WR, Carr GW (1970) Aerodynamic characterisitcs of

exposed rotating wheels. Technical report 1970/2

Thisse E (2004) Influence of end plates on tip vortices in ground

effect for a 2004 formula one front wing. M.Sc., Cranfield

College of Aeronautics, Cranfield University

Zerihan J, Zhang J (2000) Aerodynamics of a single element wing in

ground effect. J Aircr 6(37):10581064

Zerihan J, Zhang J (2003) Off-surface measurements of a wing in

ground effect. J Aircr 40(4):716725

Zhang X, Toet W, Zerihan J (2006) Ground effect aerodynamics of

race cars. Appl Mech Rev, 3349

546 Exp Fluids (2008) 45:537546

123

Experimental investigation into wing span and angle-of-attack effects on sub-scale race car wing/wheel interaction aerodynamicsAbstractIntroductionExperimental setup and apparatusInverted wing and wheel geometryExperimental setup

Results and discussionWheel without wing, comparison of stationary and rotating wheelWheel and wing, wing span 100%Wheel and wing, wing span 0%

ConclusionReferences

/ColorImageDict > /JPEG2000ColorACSImageDict > /JPEG2000ColorImageDict > /AntiAliasGrayImages false /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 150 /GrayImageDepth -1 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict > /GrayImageDict > /JPEG2000GrayACSImageDict > /JPEG2000GrayImageDict > /AntiAliasMonoImages false /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 600 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict > /AllowPSXObjects false /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile (None) /PDFXOutputCondition () /PDFXRegistryName (http://www.color.org?) /PDFXTrapped /False

/Description >>> setdistillerparams> setpagedevice