5 ~: U! d) s8 M% ^musk 要的速度就是700mph。300mph是近期实验目标。300mph也基本是露天高速磁悬浮的速度。他在proposal里说的规避那个极限需要的极高速（really really fast)是指 several thousand miles per hour。非常明确的。
xlan1976 发表于 2017-10-17 23:45$ O% K$ l y: v+ g( p
700mph的话，正好是这个limit适用的范围，怎么设计就有各种脑洞可开了。7 Y+ P1 i, o( C0 o8 g' M( ]
several thousand miles per hou ...
. S& h8 R8 w- E4 f( A. T我认为局部激波问题也不大。激波应主要作用在轨道上面。musk的想法是通过前端风扇压缩，然后向下排形成气垫，并通过这个气垫通道把空气导向后方。激波最大可能是在那个V字形轨道上。而这个轨道的主受力点是在桩子上，不是管道上。还有要么就是头部的风扇那里。那就直接在车体内解决掉了激波。
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如果车体跟管道间是密封的，车体前端全部气体流过风扇，就会像你说的这样。但车体如果跟管道间不是密封的，不能保证全部气流经过风扇，就会有影响，影响有多大要看具体设计。: p4 O9 |+ z. d
另外，如果是车体前端全部气体流过风扇，风扇进口处必须是亚音速气流，不然超过当前技术设计能力了，因此进气道设计是重要的，不过700mph的话，普通的亚音速皮托管式进气道应该就可以了，虽然难免在进气道前面出现正激波，但在M<1.5的情况下还可以接受，至少对飞机是这样。其实如果采用超音速进气道，通过一系列斜激波来将气流减速为亚音速流的话，我觉得这个方式在低真空度的情况下实现一定范围的超音速也是可以的。
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musk 的 electric compressor fan 在其计划书里是这么描述 （其中的一种）：. y( L9 Q9 v. ^4 b. }/ X6 z) K- k
. R. S( b& O& XHyperloop Passenger Capsule . R1 `& t+ {; n1. Tube air is compressed with a compression ratio of 20:1 via an axial compressor. 7 l; p- R! D* K& U2. Up to 60% of this air is bypassed: 2 h1 L0 w7 i$ n7 Q* H: }/ V- O- B& na. The air travels via a narrow tube near bottom of the capsule to the tail. / n: A' y2 n* Y. O% ib. A nozzle at the tail expands the flow generating thrust to mitigate some of the small amounts of aerodynamic and bearing drag. 5 z! s8 `- }/ G6 K1 j: P1 d# Y3. Up to 0.44 lb/s (0.2 kg/s) of air is cooled and compressed an additional 5.2:1 for the passenger version with additional cooling afterward. ' [ y" s# z% Za. This air is stored in onboard composite overwrap pressure vessels. ; Q3 I: c7 u$ s/ Y1 b, e3 F
b. The stored air is eventually consumed by the air bearings to maintain distance between the capsule and tube walls. % O. Y9 s4 a5 n% L2 r4. An onboard water tank is used for cooling of the air. & I! h2 b. H+ O9 p! I da. Water is pumped at 0.30 lb/s (0.14 kg/s) through two intercoolers (639 lb or 290 kg total mass of coolant). 2 P3 O) Y5 M6 M5 _3 g1 @
b. The steam is stored onboard until reaching the station. . x- O: u0 ^6 q* mc. Water and steam tanks are changed automatically at each stop. & M" M; {: S3 O. P! t' U5. The compressor is powered by a 436 hp (325 kW) onboard electric motor: J6 H" w+ h9 T8 T' g! s
a. The motor has an estimated mass of 372 lb (169 kg), which includes power electronics. 7 ^$ f9 p3 Y) Y/ {- v' d+ q7 E# mb. An estimated 3,400 lb (1,500 kg) of batteries provides 45 minutes of onboard compressor power, which is more than sufficient for the travel time with added reserve backup power. 7 G$ g3 W2 L4 K7 J2 G) s2 ~: Hc. Onboard batteries are changed at each stop and charged at the stations.
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发表于 2017-10-18 12:30:25
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