Vane type changes how quickly the arrow settles in flight

The summary today

That the vanes are what straightens the arrow is well measured, and three different laboratories find that vane type changes how quickly they do it. In 2011, in the United Kingdom, the same arrow shot from a machine with vanes 24 per cent larger oscillates with a period 12 per cent shorter and damps sooner. In a magnetic suspension wind tunnel, where the arrow is held in the air by magnetic fields rather than supports, lift and the moment that realigns the arrow grow in proportion to its incidence, and the centre of pressure falls a few centimetres in front of the fletching: almost all of the restoring force comes from there. In the same tunnel Spin Wings give more lift and more moment than Gas Pros, in proportion to their area, and straighten the arrow faster; going from small to large straight vanes, the frequency of the oscillation rises from 4 to 5.3 hertz. The broadest comparison, eight commercial vanes and thirty-two prototypes, finds that the most widely used vane in the world brings the arrow from forty-five degrees of incidence back to zero in 0.934 seconds against 1.283 for an average vane, and that the vanes that spin the arrow most are not the ones that straighten it first. The evidence is still limited, though: almost all the tests come from the same wind tunnel programme, none has statistics on the differences between vanes, only two were run outside the tunnel, and nobody has yet put two different vanes on the same target and counted the points.

Also phrased as: "vanes straighten the arrow"; "large or small vanes"; "how much vane type matters"; "one vane settles the arrow sooner than another"; "what vanes are for"

Evidence

• 2011
  For Equipment tests Published later

  Competition X10 and A/C/E arrows with Spin Wing vanes in JAXA's 60 cm magnetic suspension tunnel, with the angle set between minus three and plus three degrees: lift grows in proportion to the angle of attack and comes mainly from the vanes, and as soon as the arrow tilts a pitching moment of stabilising sign appears, also proportional to the angle. The slope of that moment is smaller for the X10, so the stubbier A/C/E shaft turns out more stable. The shaft's slenderness changes drag and moment but not lift. No archers and no target.

  A10 Aerodynamic Properties of an Archery Arrow : JAXA's 60cm MSBS Experiments · Yuta Komori, Keita Mukaiyama, Takeshi Miyazaki, Hiroki Sugiura

• 2011
  For Equipment tests Published later

  A crossbow bolt tested with three point shapes, in free flight with a compressed-air launcher and two high-speed cameras and in the magnetic suspension tunnel: at a Reynolds number of 0.8 times 10 to the sixth, lift rises and the pitching moment falls linearly with the angle, that is the vanes generate the moment that brings the shaft back into line, and the effect of point shape on lift and moment is negligible. It is not an archery arrow, but the geometry is the same.

  Aerodynamic properties of an arrow: Influence of point shape on the boundary layer transition · Keita Mukaiyama, Kazuhiko Suzuki, Takeshi Miyazaki, Hideo Sawada

• 2011
  For Equipment tests Published later

  The same arrow, a Protour 470, shot from a shooting machine with two different vanes, its attitude in flight reconstructed from paper tears and compared with a model: with Titeflight vanes, 24 per cent larger in area than X vanes, the period of oscillation is 12 per cent shorter (19.4 metres, or 0.25 seconds, against 21.8 metres, 0.28 seconds), the amplitude is smaller and the damping faster, slightly more than the calculation predicts. Without vanes the arrow stays stable but oscillates with a period of about 80 metres, and at 15 metres it lands 4.5 centimetres to the right of the fletched arrow, against the 4.4 predicted.

  Arrow behaviour in free flight · J L Park

• 2012
  Context Equipment tests Published later

  An Easton A/C/E arrow in the wind tunnel: the lift coefficient grows with the angle of attack at a slope of about 0.69 per degree and the pitching moment coefficient at about minus 0.31 per degree, at a Reynolds number of 1.1 times 10 to the fourth, both independent of point shape. The centre of lift falls about 30 cm behind the centre of mass, that is about 3 cm ahead of the vanes: they supply nearly all of the force that straightens the arrow. It explains the mechanism without comparing vanes.

  Aerodynamic properties of an archery arrow · Takeshi Miyazaki, Keita Mukaiyama, Yuta Komori, Kyouhei Okawa, Satoshi Taguchi, Hiroki Sugiura

• 2013
  For Equipment tests Published later

  Easton A/C/E arrows tested with two different vanes in free flight and in the magnetic suspension tunnel: with Gas Pro vanes the arrow did not spin and the air layer stayed laminar up to the highest Reynolds number tested, with a drag coefficient near the laminar value of 1.6, while with Spin Wings it spun and the layer turned turbulent. The angle of attack beyond which the change happens is about 0.6 degrees with Spin Wings and slightly higher with Gas Pro vanes, the same for ogival and tapered points. It is the first direct comparison between two commercial vanes, from a single bench.

  Free Flight and Wind Tunnel Measurements of the Drag Exerted on an Archery Arrow · K. Okawa, Y. Komori, T. Miyazaki, S. Taguchi, H. Sugiura

• 2014
  Context Equipment tests Published later

  Static tests on an arrow model with and without vanes and with vanes at different angles, in a conference paper from a venue with questionable editorial standards: with vanes the lift and pitching moment change considerably, and changing the vane angle changes the lift considerably, but the paper gives no numerical values and does not measure how the arrow settles in flight. It confirms that the vanes provide stability, without comparing different types.

  Experimental Hydro- and Aerodynamics Research on Arrow Questionable venue · Xiao An Long

• 2015
  For Equipment tests Published later

  A/C/E arrows with Spin Wing and Gas Pro vanes, magnetic suspension tunnel, free flight with an air launcher and numerical calculation: in flight at a Reynolds number of 1.5 times 10 to the fourth the Spin Wings keep the angle of attack smaller and make it oscillate faster, and the slope of the pitching moment is larger with them, that is they stabilise better; the simulation over 70 m points the same way at every speed. It is the Gas Pro vanes instead that spin the arrow faster (spin parameter 0.039 against 0.029). In the calculation of vertical scatter at 70 m, the scatter falls as the slope of the restoring moment rises and as that of the lift falls, that is the vane that suits accuracy is one with little lift and a large restoring moment. It points the opposite way to the 2013 comparison on which vane is better.

  The relation between the boundary layer transition and the attitude of archery arrow · T. Matsumoto, R. Ando, J. Ortiz, T. Miyazaki, S. Taguchi

• 2016
  Context Equipment tests Published later

  A/C/E arrows with Spin Wing and Gas Pro vanes in JAXA's magnetic suspension tunnel, with the angle varied between minus three and plus three degrees: lift and pitching moment stay proportional to the angle and the slope barely depends on the Reynolds number, so much so that the values at 7.7 times 10 to the third were used in the calculations for both vanes. The oscillation's own damping turns out to be negligible, of the order of 10 to the minus six. The same programme of tests as the 2015 work, so it is not an independent confirmation.

  The boundary layer transition and the attitude of archery allow · Takamasa Matsumoto, Ryu Ando, Takeshi Miyazaki, Satoshi Taguchi, Hiroki Sugiura

• 2017
  For Equipment tests Published later

  A/C/E arrows with Spin Wing and Gas Pro vanes in the magnetic suspension wind tunnel, at a Reynolds number of 7.7 times 10 to the third: the lift and pitching moment slopes are 40.2 and 16.2 per radian with Spin Wings, 29.6 and 11.1 with Gas Pros, in a ratio (0.74 and 0.69) close to that of the two vanes' areas (0.75). In the simulation over 70 metres the arrow with Spin Wings oscillates at 3.95 hertz against 3.28 and damps the oscillation at 0.92 against 0.68 per second: the larger vane straightens it faster.

  Indeterminacy of drag exerted on an arrow in free flight: arrow attitude and laminar-turbulent transition · T Miyazaki, T Matsumoto, R Ando, J Ortiz, H Sugiura

• 2018
  Context Model Published later

  A simulation of an A/C/E arrow's flight over 70 m, with the aerodynamic parameters taken from the tunnel measurements: in a 3 m/s crosswind the maximum angle of attack is 3.0 degrees, it oscillates at 3.59 hertz and dies away at 0.87 per second thanks to the vanes, with the oscillation strongest over the first twenty metres, that is the first four tenths of a second. The damping rate does not change with the strength of the crosswind. It is a calculation, not a new measurement.

  Trajectory and attitude of an archery arrow in free flight:: estimation of the influence of the background wind. · Julio Ortiz, Masato Ando, Takeshi Miyazaki

• 2019
  For Equipment tests Published later

  A 100 mm arrow model released from 45 degrees of incidence in a wind tunnel at 20 m/s, eight commercial vanes and thirty-two prototypes. Time to return to zero plus or minus five per cent: 0.934 s with the most widely used vane in the world against 1.283 s for an average commercial vane. Vanes without a twist at the tip lose spin once the oscillation has died down (37.31 revolutions per second during the oscillation against 24.75 afterwards, down 33.7 per cent; with a twist at the tip 42.74 against 34.97, down 18.2 per cent), because the vanes' own angle of attack returns to zero. Among the prototypes, nearly all larger than the commercial vanes, the wider surfaces settle sooner, and the trend between spin and settling time runs the other way. The thirty-two vanes with surface texture alone, with no curvature, show no clear differences between textures, and in seven cases out of thirty-two they do not spin or do not converge at all. No statistical tests, a regional venue, and 20 m/s is about a third of the arrow's real speed.

  A consideration on the relationship between the vain shape and the rotation and vibration of shaft of Archery · Takanori Hirano

• 2019
  For Review Published later

  A review of the effects of the atmosphere on target archery: the main contribution to the arrow's behaviour in flight comes from the lift of the vanes, which act on a far longer lever arm than the drag does, and the period of pitch and yaw oscillation calculated on that basis matches the measured one, as does the rate at which the amplitude dies away. It gives the physical reason, not a comparison between vanes.

  The impact of the atmosphere on target archery · James L Park

• 2020
  For Equipment tests Published later

  A/C/E 1206 arrows with Easton Diamond straight vanes of 175 and 280, magnetic suspension tunnel at a Reynolds number of 1.0 times 10 to the fourth, free flight over 55 m indoors with an inertial sensor inside the shaft, and a simulation calibrated on the measurements: going from the small to the large vanes, the lift coefficient goes from 39.1 to 62.1 per radian (about 60 per cent more) and the pitching moment coefficient from 18.8 to 33.9 (about 80 per cent more). With an initial speed of 56 m/s the arrow oscillates at 5.3 hertz instead of 4 and the maximum angle of attack falls from 0.36 to 0.27 degrees. In the simulations, with the pitching moment taken close to zero the oscillation nearly disappears and the angle of attack goes above three degrees, ten times the real values. It is the most quantitative measurement of the link between vane size and settling speed, still without archers.

  Experimental and Computational Study of Archery Arrows Fletched with Straight Vanes · Julio Ortiz, Atsushi Serino, Toshinari Hasegawa, Takahito Onoguchi, Hiroki Maemukai, Takeshi Miyazaki, Hiroki Sugiura

• 2020
  For Equipment tests Published later

  Wooden arrows shot from a 48 lb elm bow fixed on a mechanical device, speed measured at 1 and 6 metres: of the two unfletched arrows one breaks at the first impact and the other gives a single valid measurement, the fastest launch of all (44.93 metres per second) but with a flight so unstable that the test is stopped, and it loses 12.70 per cent of its energy over 5 metres, more than the arrow with the largest fletching. The authors also note that a small fletching straightens the arrow less quickly than a large one. It does not measure attitude, and there is no inferential statistics.

  The important role of bow choice and arrow fletching in projectile experimentation. A ballistic approach · Christian Lepers, Veerle Rots

Status history

1. 2011 Reported The first measurements come from two laboratories. In a magnetic suspension wind tunnel lift grows in proportion to the angle of attack and is produced almost entirely by the vanes, which generate a moment that realigns the arrow with the flow. In the United Kingdom, the same arrow shot from a machine with two different vanes answers the question directly: with vanes 24 per cent larger the period of oscillation shortens by 12 per cent and the damping is faster. It is a single comparison between vanes, on two models, so the evidence in favour is there and it is limited: reported.
2. 2012 Reported What gets measured is where the force that straightens the arrow comes from, not yet the difference between vanes: the centre of pressure falls a few centimetres ahead of the fletching, so the vanes supply nearly all of the restoring force, and the moment that realigns the shaft grows in proportion to the angle. On the question itself, whether one vane straightens the arrow faster than another, there is still no evidence, and the status stays where it was.
3. 2013 Reported The first comparison between two vanes in the wind tunnel: with Gas Pros the arrow does not spin and keeps the boundary layer attached up to the highest speed tested, and a larger angle of attack than with Spin Wings is needed to lose it. The two vanes do not behave the same way, but the test looks at spin and the boundary layer, not at how fast the arrow settles, so the status stays where it was.
4. 2014 Reported A conference paper from a venue with questionable editorial standards finds, in static tests, that with vanes lift and moment change considerably and that the vane angle changes the lift considerably, with no numerical values and no measurement of settling in flight. It confirms the role of the vanes but does not compare different types, and a questionable venue does not move the status.
5. 2015 Reported The second direct comparison of how fast the arrow settles arrives, from a different laboratory from the 2011 one: in the magnetic suspension wind tunnel Spin Wings keep the incidence smaller and make it oscillate faster than Gas Pros, and the simulation over seventy metres points the same way; the calculation also indicates that the vane best suited to accuracy generates little lift and a large restoring moment. Two laboratories now point the same way, but the 2011 comparison covers only two vanes and the wind tunnel one comes from the group behind almost all the other tests, with no statistics on the differences: the evidence is still limited and the status stays reported.
6. 2016 Reported Lift and pitching moment grow in proportion to the angle of attack, with a slope that does not change with the arrow's speed: this is the mechanism by which the vane straightens it, and it holds across the whole range of competition speeds. It explains the how without adding a comparison between vanes, so the status holds.
7. 2017 Reported The same wind tunnel programme measures the two commercial vanes side by side: Spin Wings give more lift and more restoring moment than Gas Pros, in proportion to their area, and in the simulation they oscillate at 3.95 rather than 3.28 hertz and damp the oscillation faster. It points the same way as 2015 and clears up the doubt left by the 2013 comparison, which looked at spin rather than settling. It is, though, the same programme of tests as in 2015 and 2016, so it does not add a laboratory: the status stays reported.
8. 2018 Reported A calculation puts a figure on the damping the vanes provide, 0.87 per second in a crosswind, and finds that it does not depend on how strong the wind is. It is a simulation calibrated on wind tunnel measurements, so it leaves the status where it was.
9. 2019 Reported The wide comparison arrives: eight commercial vanes and thirty-two prototypes in the same tunnel. The most widely used vane in the world brings the arrow back from forty-five degrees to zero in 0.934 seconds against 1.283 for an average commercial vane; vanes without a twist at the tip lose a third of their spin once the oscillation has died down; vanes with a larger surface settle sooner, and the ones that spin the arrow most are not the ones that straighten it soonest. Among the thirty-two with surface texture alone, with no curvature, one in four does not spin or does not settle at all. A review from the same year adds the mechanism: what counts is the lift of the vanes, which act on a far longer lever arm than the drag does. Many consistent tests, one tunnel, no archers: it stays reported.
10. 2020 Reported The measurement becomes quantitative: going from small to large straight vanes, lift grows by about sixty per cent and the pitching moment by about eighty, the arrow oscillates at 5.3 rather than 4 hertz and the maximum incidence falls from 0.36 to 0.27 degrees. From Belgium comes the extreme case: a wooden arrow without fletching, shot from a machine, flies so unstably that the test is stopped, and the authors note that a small fletching straightens the arrow less quickly than a large one. Three laboratories now point the same way, but none of these tests has statistics on the differences between vanes, the tests outside the wind tunnel are two and the second does not measure attitude, and there is nothing on archers: the status stays reported.

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Research lines

• 32 studiesArrow aerodynamics: drag, boundary layer, vanes
• 29 studiesThe archer's paradox in research: from 1987 to today

Other claims in this domain

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• CorroboratedAs it leaves the bow, the arrow flexes and snakes around the riser instead of leaving straight19 studies · 47 archers measuredStatus since 2012
• ReportedA camera-based scoring system misreads some arrows: the ones barely sticking out and the ones that shift the target face7 studies · 2 archers measuredStatus since 2017
• ReportedA chest band with fibre optic sensors measures breathing and mean heart rate with small errors, and an archer can wear it while shooting2 studiesStatus since 2019
• ReportedA compound bow stores between 70 and 100 joules and sheds about two thirds of the force at full draw4 studiesStatus since 2015

See all claims on equipment and tuning