By Xie Shudi, Student News Agency

On December 16, 2015, Chief Scientist Daniel Weihs from Israeli Ministry of Science & Technology was invited to the 49th session of SUSTC Lectures to lecture on aerodynamics in the biology field. The lecture was chaired by SUSTC Chief Logistics Officer Lu Chun.

Professor Daniel Weihs

Professor Daniel Weihs is the specially-recruited professor at Israel Institute of Technology, member of Steering Committee in Israeli Space Agency and principal of Robot Technology Project. In 1971, Professor Weihs received the Ph.D. Degree from Israel Institute of Technology. He used to work as the Chairman of Israel National Committee on Space Researches. Professor Daniel Weihs is also the academician of Israel Academy of Science and Culture, foreign associate of US National Academy of Engineering, Chairman of Israel Inter-university Ocean Science Institute, and member of National Druck Management Forum Consultancy Committee.

Lecture details

In the beginning of the lecture, Mr. Lu Chun introduced the relations between Professor Daniel Weihs and China. As a Jew, the father of Professor Daniel Weihs was forced to come to China in 1939. Professor Daniel Weihs, after he was born in Guilin in 1941, followed his parents to move to Kunming and Shanghai before they went back to Israel in 1949.

From animal gliding phenomenon to airfoil effect and flapping flight

In the beginning of the lecture, Professor Daniel Weihs showed some gliding phenomena in a vivid and humorous way. For instance, “the bat, when opening its wings, can glide from one tree to another”. And there are some seeds, insects, birds, bats and other mammals and reptiles that have wings or wing-like villus. As Professor Daniel Weihs said, “It was only 5-10 years ago when the gliding of reptiles was first mentioned because people didn’t believe snakes could fly.” When talking about gliding, the Professor also mentioned airfoil effect. After introducing briefly the leading edge vortex effect. By using photos, he explained the state of wings at different speeds and influence of wingtips on flight.

After explaining the gliding that does not need force, Professor Daniel Weihs introduced the flapping flight that needs force. “This is a very interesting part”, the Professor played a short video clip to show mimicking of the flapping flight.

From the animal energy saving to the optimal aircraft formation

Energy use and saving “is another interesting part”. Birds, or even fishes, have their ways of saving energy. Professor Daniel Weihs showed many means of using energy. For instance, birds can use the rising hot air to glide upwards. They can also use the air flow to help them stay at a certain height. The Professor showed accurate data graph, revealing group flight is a means of saving energy adopted by birds and fishes. Human kind also used this theory to work out the optimal aircraft formation.

Then Professor Daniel Weihs played a few video clips about experiments on pilot-less aircraft learning from small insects. After explaining an application case of “foxfish” car, the Professor introduce dolphin saving energy. He explained the case in which the younger dolphin unable to follow the adult dolphin jumping out of water in a vivid and easy-to-understand way.

After explaining the origin of wind-tunnel test, Professor Daniel Weihs ended his lecture by showing the photo of a lovely dolphin. After that, he patiently answered questions raised by the students. At the end of the lecture, many students were still raising their questions to the Professor.