2.3 Aero­dy­nam­ics

The pri­mary fac­tor lim­it­ing the max­i­mum speed of a Mi­ata is aero­dy­namic re­sis­tance. This re­sis­tance is re­lated to bound­ary lay­ers along the sur­face of the Mi­ata in which the air is be­ing dragged along. Go­ing down­stream, this air forms a wake be­hind the Mi­ata. The wake is the pri­mary cause of re­sis­tance, [see 3, pp. 570-571].

The wake is al­ways rel­a­tively wide be­cause the bound­ary layer sep­a­rates from the sur­face at some point, [5,6,7]. This greatly in­creases the aero­dy­namic re­sis­tance. Con­trol­ling sep­a­ra­tion re­mains a dif­fi­cult prob­lem, as dis­cussed by Shen and Xiao [4].

There is also the prob­lem that the bound­ary layer is nor­mally tur­bu­lent. By it­self, tur­bu­lence will in­crease drag due to its ther­mo­dy­nam­i­cally ir­re­versible me­chan­ics, [9]. How­ever, of­ten tran­si­tion to tur­bu­lence de­creases drag in­stead be­cause it also tends to de­lay sep­a­ra­tion.

The high speed of, in par­tic­u­lar, white Mi­atas, will also bring in com­press­ibil­ity ef­fects, [1]. Note that such ef­fects are largest in el­e­vated speed ar­eas such as near the top of the wind­shield header.