{"id":78,"date":"2021-11-24T03:30:01","date_gmt":"2021-11-24T03:30:01","guid":{"rendered":"https:\/\/agileaircraft.com\/?page_id=78"},"modified":"2023-12-31T10:38:00","modified_gmt":"2023-12-31T10:38:00","slug":"rotor-testing","status":"publish","type":"page","link":"https:\/\/agileaircraft.com\/?page_id=78","title":{"rendered":"Rotor Testing"},"content":{"rendered":"\n

5-bladed rotor: initial test data
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5-bladed rotor mounted on measurement rig<\/figcaption><\/figure>\n\n\n\n

See a video of this test at https:\/\/www.instagram.com\/agileaircraft\/<\/a><\/p>\n\n\n\n

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Test range is limited by maximum power of 190 watts from battery<\/figcaption><\/figure>\n\n\n\n

The advantages of this 5-bladed design are<\/p>\n\n\n\n

1) Extremely quick response<\/strong><\/a>. A conventional drone must spin each rotor faster to get more lift, for example to counter a random wind gust.
A drone or aircraft with far quicker response could be used in new ways, such as very close to structures in windy conditions.<\/p>\n\n\n\n

2) Low vibration in forward flight<\/a><\/strong>. Each lift-rotor blade generates more lift when advancing than when retreating, but in a 5-bladed design, the forces cancel.<\/p>\n\n\n\n

3) Low noise<\/a><\/strong>. For the same lift and diameter, 5-blades run slower and consequently quieter<\/a> than 2-blades.<\/p>\n\n\n\n

4) Auto-rotation by default<\/strong>. For safety and simplicity, the default blade pitch is negative when not powered. The blade pitch range is readily adjustable to suit application requirements.<\/p>\n\n\n\n

If you need these advantages for your application, we may be able to supply suitable rotors. Get in touch.<\/p>\n\n\n\n

Mk2 2-bladed rotor test data:<\/h2>\n\n\n\n
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Figure 1<\/strong>: simulation of rotor speed and lift<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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Figure 2<\/strong>: simulation of blade-pitch and angle-of-attack<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

Figure 1 <\/strong>shows a simulation of the model rotor speed (RPM) and lift (grams) steady-states over a range of drive torques (Nm), using an (upublished) version of Blade-Element-Momentum-Theory (BEMT). This version approximates disk loading as a constant over an effective annulus. It conserves total angular momentum at the cost of another (possibly obscure) assumption.

The behaviour shown is for carefully selected values elastic-element tailoring. Other values can result in quite different behaviour.
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Figure 2 <\/strong>shows blade-pitch and angle-of-attack (at the tip) for the same simulation as Figure 1 <\/strong>.<\/p>\n\n\n\n

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Figure 3<\/strong>: Drive torque change with time<\/figcaption><\/figure>\n\n\n\n

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Figure 4<\/strong>: Blade-pitch and attack-angle change with time <\/figcaption><\/figure>\n\n\n\n

<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Figure 5<\/strong>: Rotor lift change with time <\/figcaption><\/figure>\n<\/div>\n\n\n\n
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Figure 6<\/strong>: Rotor speed change with time <\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

Figures 3-6<\/strong> show simulated transient behaviour for a drive torque excursion event, where aerodynamics are here approximated as a sequence of steady states. Because the starting torque of 0.2 Nm is within the range where rotor speed is approximately constant, the change shown in Figure 6 is small, with an imperceptable spin-down after the event.<\/p>\n\n\n\n

<\/p>\n\n\n\n

The Mk1 2-bladed rotor<\/h2>\n\n\n\n
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Figure 7<\/strong>: Rotor test in progress<\/figcaption><\/figure>\n\n\n\n
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Figure 8<\/strong>: Measured rotor speed<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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Figure 9<\/strong>: Measured rotor lift<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

Figures 8<\/strong> and 9<\/strong> show rotor speed and lift at torques estimated from the motor current. Since the motor was never driven at more than half-power, it is thought that this will be a good estimate. The experimental behaviour has the same character as simulated. Other simulations show that different elastic parameters could have rsulted in very different behaviour.<\/p>\n","protected":false},"excerpt":{"rendered":"

5-bladed rotor: initial test data See a video of this test at https:\/\/www.instagram.com\/agileaircraft\/ The advantages of this 5-bladed design are 1) Extremely quick response. A conventional drone must spin each rotor faster to get more lift, for example to counter a random wind gust.A drone or aircraft with far quicker response could be used in new […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-78","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/agileaircraft.com\/index.php?rest_route=\/wp\/v2\/pages\/78","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/agileaircraft.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/agileaircraft.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/agileaircraft.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/agileaircraft.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=78"}],"version-history":[{"count":11,"href":"https:\/\/agileaircraft.com\/index.php?rest_route=\/wp\/v2\/pages\/78\/revisions"}],"predecessor-version":[{"id":495,"href":"https:\/\/agileaircraft.com\/index.php?rest_route=\/wp\/v2\/pages\/78\/revisions\/495"}],"wp:attachment":[{"href":"https:\/\/agileaircraft.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=78"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}