AI Impacts Wiki

User Tools

Site Tools

You are here: Welcome to the AI Impacts Wiki! » power_of_evolution » evolution_engineering_comparison » Energy efficiency of MacCready Gossamer Albatross
power_of_evolution:evolution_engineering_comparison:energy_efficiency_of_maccready_gossamer_albatross

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

— power_of_evolution:evolution_engineering_comparison:energy_efficiency_of_maccready_gossamer_albatross [2022/09/21 07:37] (current)
Line 1: Line 1:
 +====== Energy efficiency of MacCready Gossamer Albatross ======
 +
 +// Published 09 November, 2020; last updated 10 December, 2020 //
 +
 +
 +
 +<HTML>
 +<p>The MacCready <em>Gossamer Albatross</em>:</p>
 +</HTML>
 +
 +
 +<HTML>
 +<ul>
 +<li><div class="li">covered around 2.0—4.6 m/kJ</div></li>
 +<li><div class="li">and moved mass at around 0.1882 —0.4577 kg⋅m/J</div></li>
 +</ul>
 +</HTML>
 +
 +
 +
 +===== Details =====
 +
 +
 +<HTML>
 +<p>The <strong>MacCready <em>Gossamer Albatross</em></strong> was a human-powered flying machine that crossed the English Channel in 1979.<span class="easy-footnote-margin-adjust" id="easy-footnote-1-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-1-2756" title='&amp;#8220;The&amp;nbsp;&lt;em&gt;&lt;strong&gt;Gossamer Albatross&lt;/strong&gt;&lt;/em&gt;&amp;nbsp;is a&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/Human-powered_aircraft"&gt;human-powered aircraft&lt;/a&gt;&amp;nbsp;built by&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/United_States"&gt;American&lt;/a&gt;&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/Aeronautical_engineer"&gt;aeronautical engineer&lt;/a&gt;&amp;nbsp;Dr.&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/Paul_B._MacCready"&gt;Paul B. MacCready&lt;/a&gt;&amp;#8216;s company&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/AeroVironment"&gt;AeroVironment&lt;/a&gt;. On June 12, 1979, it completed a successful crossing of the&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/English_Channel"&gt;English Channel&lt;/a&gt;&amp;nbsp;to win the second £100,000 (£509644&amp;nbsp;today)&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/Kremer_prize"&gt;Kremer prize&lt;/a&gt;.&lt;sup&gt;&lt;a href="https://en.wikipedia.org/wiki/MacCready_Gossamer_Albatross#cite_note-Gossamer_Albatross_ECN-12665-1"&gt;[1]&lt;/a&gt;&lt;/sup&gt;&amp;#8220;&lt;/p&gt; &lt;p&gt;“MacCready &lt;em&gt;Gossamer Albatross&lt;/em&gt;.” In &lt;em&gt;Wikipedia&lt;/em&gt;, October 7, 2020. &lt;a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381"&gt;https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381&lt;/a&gt;.'><sup>1</sup></a></span> The pilot pedaled the craft, seemingly as if on a bicycle. It had a gross mass of 100kg, flying across the channel,<span class="easy-footnote-margin-adjust" id="easy-footnote-2-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-2-2756" title='&amp;#8220;The empty mass of the structure was only 71&amp;nbsp;lb (32&amp;nbsp;kg), although the gross mass for the Channel flight was almost 220&amp;nbsp;lb (100&amp;nbsp;kg).&amp;nbsp;&amp;#8220;&lt;/p&gt; &lt;p&gt;“MacCready &lt;em&gt;Gossamer Albatross&lt;/em&gt;.” In &lt;em&gt;Wikipedia&lt;/em&gt;, October 7, 2020. &lt;a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381"&gt;https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381&lt;/a&gt;.'><sup>2</sup></a></span> and flew 35.7 km in 2 hours and 49 minutes.<span class="easy-footnote-margin-adjust" id="easy-footnote-3-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-3-2756" title='&amp;#8220;Allen completed the 22.2&amp;nbsp;mi (35.7&amp;nbsp;km) crossing in 2&amp;nbsp;hours and 49&amp;nbsp;minutes, achieving a top speed of 18&amp;nbsp;mph (29&amp;nbsp;km/h) and an average altitude of 5&amp;nbsp;ft (1.5&amp;nbsp;m).&amp;#8221;&lt;/p&gt; &lt;p&gt;“MacCready &lt;em&gt;Gossamer Albatross&lt;/em&gt;.” In &lt;em&gt;Wikipedia&lt;/em&gt;, October 7, 2020. &lt;a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381"&gt;https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381&lt;/a&gt;.'><sup>3</sup></a></span> The crossing was difficult however, so it seems plausible that the <em>Gossamer Albatross</em> could fly more efficiently in better conditions.</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>We do not know the pilot’s average power output, however:</p>
 +</HTML>
 +
 +
 +<HTML>
 +<ul>
 +<li><div class="li">Wikipedia claims at least 300W was required to fly the craft<span class="easy-footnote-margin-adjust" id="easy-footnote-4-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-4-2756" title='&amp;#8220;To maintain the craft in the air, it was designed with very long, tapering wings (high&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/Aspect_ratio_(wing)"&gt;aspect ratio&lt;/a&gt;), like those of a glider, allowing the flight to be undertaken with a minimum of power. In still air, the required power was on the order of 300&amp;nbsp;W (0.40&amp;nbsp;hp), though even mild turbulence made this figure rise rapidly.&lt;sup&gt;&lt;a href="https://en.wikipedia.org/wiki/MacCready_Gossamer_Albatross#cite_note-2"&gt;[2]&lt;/a&gt;&lt;/sup&gt;&amp;#8220;&lt;br&gt;&lt;br&gt;“MacCready &lt;em&gt;Gossamer Albatross&lt;/em&gt;.” In &lt;em&gt;Wikipedia&lt;/em&gt;, October 7, 2020. &lt;a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381"&gt;https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;amp;oldid=982283381&lt;/a&gt;.'><sup>4</sup></a></span></div></li>
 +<li><div class="li">Chung 2006, an engineering textbook, claims that the driver, a cyclist, could produce around 200W of power.<span class="easy-footnote-margin-adjust" id="easy-footnote-5-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-5-2756" title="Chung, Yip-Wah. &lt;em&gt;Introduction to Materials Science and Engineering&lt;/em&gt;. CRC Press, 2006. p89"><sup>5</sup></a></span></div></li>
 +<li><div class="li">Our impression is that 200W is a common power output over houres for amateur cycling. For instance, one of our researchers is able to achieve this for three hours.<span class="easy-footnote-margin-adjust" id="easy-footnote-6-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-6-2756" title="https://www.strava.com/activities/272615649/overview"><sup>6</sup></a></span></div></li>
 +</ul>
 +</HTML>
 +
 +
 +<HTML>
 +<p>The best documented human cycling wattage that we could easily find is from professional rider Giulio Ciccone who won a stage of the Tour de France, then uploaded power data to the fitness tracking site Strava.<span class="easy-footnote-margin-adjust" id="easy-footnote-7-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-7-2756" title='Strava. “Yellow Jersey &amp;#8211; Giulio Ciccone’s 158.8 Km Bike Ride.” Accessed November 9, 2020. &lt;a href="https://www.strava.com/activities/2525139293"&gt;https://www.strava.com/activities/2525139293&lt;/a&gt;.'><sup>7</sup></a></span> His performance suggests around 318W is a reasonable upper bound, supposing that the pilot of the <em>Gossamer Albatross</em> would have had lower performance.<span class="easy-footnote-margin-adjust" id="easy-footnote-8-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-8-2756" title="For an upper value, we used a combination of two metrics given on the website. The first metric is his “weighted average power” for the Tour de France stage, which was 318W. Weighted average power is a way of averaging power over a ride with highly variable power which gives higher weight to higher power portions of the ride, and is used by athletes and coaches to estimate the maximum power that a rider could sustain for a long time, if they had a steady power output. The second metric is Ciccone’s maximum power from his Tour race applied over the duration of the MacCready flight (2 hours and 40 min) which is 5W/kg body weight. For the pilot, Allen, riding with the same power per body weight (65 kg), this would be equivalent to 322W, a similar value to his weighted average power. We use the lower of the two values, 318W."><sup>8</sup></a></span></p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>To find the energy used by the cyclist, we divided power output by typical efficiency for a human on a bicycle, which according to Wikipedia ranges from .18 to .26.<span class="easy-footnote-margin-adjust" id="easy-footnote-9-2756"></span><span class="easy-footnote"><a href="#easy-footnote-bottom-9-2756" title='&amp;#8220;The required food can also be calculated by dividing the output power by the&amp;nbsp;&lt;a href="https://en.wikipedia.org/wiki/Muscle#Efficiency"&gt;muscle efficiency&lt;/a&gt;. This is 18–26%.&amp;nbsp;&amp;#8220;&lt;/p&gt; &lt;p&gt;“Bicycle Performance.” In &lt;em&gt;Wikipedia&lt;/em&gt;, October 9, 2020. &lt;a href="https://en.wikipedia.org/w/index.php?title=Bicycle_performance&amp;amp;oldid=982652996"&gt;https://en.wikipedia.org/w/index.php?title=Bicycle_performance&amp;amp;oldid=982652996&lt;/a&gt;.'><sup>9</sup></a></span></p>
 +</HTML>
 +
 +
 +==== Distance per Joule ====
 +
 +
 +<HTML>
 +<p>For distance per energy this gives us a highest measure of:</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>35.7 km / ((200W * (2 hours + 49 minutes))/0.26) = 4,577 m/MJ</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>And a lowest measure of:</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>35.7 km / ((318W * (2 hours + 49 minutes))/0.18) = 1,993 m/MJ</p>
 +</HTML>
 +
 +
 +==== Mass per Joule ====
 +
 +
 +<HTML>
 +<p>For weight times distance per energy this gives us a highest measure of:</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>(100kg * 35.7 km) / ((200W * (2 hours + 49 minutes))/0.26) = 0.4577 kg⋅m/j</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>And a lowest measure of:</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p>(100kg * 35.7 km) / ((318W * (2 hours + 49 minutes))/0.17) =  0.1882 kg⋅m/j</p>
 +</HTML>
 +
 +
 +<HTML>
 +<p><br/>
 +<br/>
 +<em>Primary author: Ronny Fernandez</em></p>
 +</HTML>
 +
 +
 +===== Notes =====
 +
 +
 +<HTML>
 +<ol class="easy-footnotes-wrapper">
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-1-2756"></span>“The <em><strong>Gossamer Albatross</strong></em> is a <a href="https://en.wikipedia.org/wiki/Human-powered_aircraft">human-powered aircraft</a> built by <a href="https://en.wikipedia.org/wiki/United_States">American</a> <a href="https://en.wikipedia.org/wiki/Aeronautical_engineer">aeronautical engineer</a> Dr. <a href="https://en.wikipedia.org/wiki/Paul_B._MacCready">Paul B. MacCready</a>‘s company <a href="https://en.wikipedia.org/wiki/AeroVironment">AeroVironment</a>. On June 12, 1979, it completed a successful crossing of the <a href="https://en.wikipedia.org/wiki/English_Channel">English Channel</a> to win the second £100,000 (£509644 today) <a href="https://en.wikipedia.org/wiki/Kremer_prize">Kremer prize</a>.<sup><a href="https://en.wikipedia.org/wiki/MacCready_Gossamer_Albatross#cite_note-Gossamer_Albatross_ECN-12665-1">[1]</a></sup>“
 +                  <p>“MacCready <em>Gossamer Albatross</em>.” In <em>Wikipedia</em>, October 7, 2020. <a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381">https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381</a>.<a class="easy-footnote-to-top" href="#easy-footnote-1-2756"></a></p>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-2-2756"></span>“The empty mass of the structure was only 71 lb (32 kg), although the gross mass for the Channel flight was almost 220 lb (100 kg). “
 +                  <p>“MacCready <em>Gossamer Albatross</em>.” In <em>Wikipedia</em>, October 7, 2020. <a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381">https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381</a>.<a class="easy-footnote-to-top" href="#easy-footnote-2-2756"></a></p>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-3-2756"></span>“Allen completed the 22.2 mi (35.7 km) crossing in 2 hours and 49 minutes, achieving a top speed of 18 mph (29 km/h) and an average altitude of 5 ft (1.5 m).”
 +                  <p>“MacCready <em>Gossamer Albatross</em>.” In <em>Wikipedia</em>, October 7, 2020. <a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381">https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381</a>.<a class="easy-footnote-to-top" href="#easy-footnote-3-2756"></a></p>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-4-2756"></span>“To maintain the craft in the air, it was designed with very long, tapering wings (high <a href="https://en.wikipedia.org/wiki/Aspect_ratio_(wing)">aspect ratio</a>), like those of a glider, allowing the flight to be undertaken with a minimum of power. In still air, the required power was on the order of 300 W (0.40 hp), though even mild turbulence made this figure rise rapidly.<sup><a href="https://en.wikipedia.org/wiki/MacCready_Gossamer_Albatross#cite_note-2">[2]</a></sup>“<br/>
 +<br/>
 +                  “MacCready <em>Gossamer Albatross</em>.” In <em>Wikipedia</em>, October 7, 2020. <a href="https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381">https://en.wikipedia.org/w/index.php?title=MacCready_Gossamer_Albatross&amp;oldid=982283381</a>.<a class="easy-footnote-to-top" href="#easy-footnote-4-2756"></a>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-5-2756"></span>Chung, Yip-Wah. <em>Introduction to Materials Science and Engineering</em>. CRC Press, 2006. p89<a class="easy-footnote-to-top" href="#easy-footnote-5-2756"></a>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-6-2756"></span>https://www.strava.com/activities/272615649/overview<a class="easy-footnote-to-top" href="#easy-footnote-6-2756"></a>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-7-2756"></span>Strava. “Yellow Jersey – Giulio Ciccone’s 158.8 Km Bike Ride.” Accessed November 9, 2020. <a href="https://www.strava.com/activities/2525139293">https://www.strava.com/activities/2525139293</a>.<a class="easy-footnote-to-top" href="#easy-footnote-7-2756"></a>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-8-2756"></span>For an upper value, we used a combination of two metrics given on the website. The first metric is his “weighted average power” for the Tour de France stage, which was 318W. Weighted average power is a way of averaging power over a ride with highly variable power which gives higher weight to higher power portions of the ride, and is used by athletes and coaches to estimate the maximum power that a rider could sustain for a long time, if they had a steady power output. The second metric is Ciccone’s maximum power from his Tour race applied over the duration of the MacCready flight (2 hours and 40 min) which is 5W/kg body weight. For the pilot, Allen, riding with the same power per body weight (65 kg), this would be equivalent to 322W, a similar value to his weighted average power. We use the lower of the two values, 318W.<a class="easy-footnote-to-top" href="#easy-footnote-8-2756"></a>
 +</div></li>
 +<li><div class="li">
 +<span class="easy-footnote-margin-adjust" id="easy-footnote-bottom-9-2756"></span>“The required food can also be calculated by dividing the output power by the <a href="https://en.wikipedia.org/wiki/Muscle#Efficiency">muscle efficiency</a>. This is 18–26%. “
 +                  <p>“Bicycle Performance.” In <em>Wikipedia</em>, October 9, 2020. <a href="https://en.wikipedia.org/w/index.php?title=Bicycle_performance&amp;oldid=982652996">https://en.wikipedia.org/w/index.php?title=Bicycle_performance&amp;oldid=982652996</a>.<a class="easy-footnote-to-top" href="#easy-footnote-9-2756"></a></p>
 +</div></li>
 +</ol>
 +</HTML>
 +
 +
  
power_of_evolution/evolution_engineering_comparison/energy_efficiency_of_maccready_gossamer_albatross.txt · Last modified: 2022/09/21 07:37 (external edit)

Page Tools

Except where otherwise noted, content on this wiki is licensed under the following license: CC0 1.0 Universal
CC0 1.0 Universal Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki