A***D
发帖数: 64 | 1 Senior Development Engineer
Job Category: Engineering & Science Location: US - California
Job ID #: 27245 Region: Altair - U.S.
Description
Altair empowers client innovation and decision-making through technology
that optimizes the analysis, management and visualization of business and
engineering information. Privately held with more than 2,000 employees,
Altair has offices throughout North America, South America, Europe and Asia/
Pacific. With a 30-year-plus track r... 阅读全帖 |
|
A***D
发帖数: 64 | 2 Senior Development Engineer
Job Category: Engineering & Science Location: US - California
Job ID #: 27245 Region: Altair - U.S.
Description
Altair empowers client innovation and decision-making through technology
that optimizes the analysis, management and visualization of business and
engineering information. Privately held with more than 2,000 employees,
Altair has offices throughout North America, South America, Europe and Asia/
Pacific. With a 30-year-plus track r... 阅读全帖 |
|
l***o
发帖数: 7937 | 3 飞机为什么会飞？这个题目太大了，需要考虑的情况太多了。
从飞机类型考虑，Rotor aircraft和Wing aircraft不同； 同样是Wing aircraft，民用机又和军用机不同（军用机的速度高很多，姿势要求多，甚至需要360度翻转）； 同样是军用机，陆地起飞的战机和母舰起飞的战机也不同（后者起飞距离短，甚至需要垂直起降）； 同样是军用飞机，subsonic,transonic, supersonic, hypersonic, high-hypersonic又不一样；同样是一般商用民航机，不同的angle of attack情况也会不同（随着AoA的增大，气流会与airfoil的上表面分离，出现turbulence甚至whirlpool）。（当然啦，如果你是一个aerodynimics的专家，你会以说，这些本质都一样，因为都是N-S方程govern的。）
就拿一个flight cycle来看,起飞、巡航、控制和降落也不一样。这个题目至少包含四层意思：（1）飞机怎么能飞起来？（takeoff）（2）飞机在天上巡航，为什么不掉下来（cruise)？（3）飞机如何调整高度和转向（... 阅读全帖 |
|
b*p
发帖数: 242 | 4 赞！菠萝飞行器设计制造系的？
我想问一下又没有人考虑过设计仿hummingbird的飞行器？
民用机又和军用机不同（军用机的速度高很多，姿势要求多，甚至需要360度翻转）；
同样是军用机，陆地起飞的战机和母舰起飞的战机也不同（后者起飞距离短，甚至需要
垂直起降）； 同样是军用飞机，subsonic,transonic, supersonic, hypersonic,
high-hypersonic又不一样；同样是一般商用民航机，不同的angle of attack情况也会
不同（随着AoA的增大，气流会与airfoil的上表面分离，出现turbulence甚至
whirlpool）。（当然啦，如果你是一个aerodynimics的专家，你: 会以说，这些本质
都一样，因为都是N-S方程govern的。）
四层意思：（1）飞机怎么能飞起来？（takeoff）（2）飞机在天上巡航，为什么不掉
下来（cruise)？（3）飞机如何调整高度和转向（flight control)?(4)飞机如何降落
（landing）？估计这些都不是楼主的意思。楼主要问的是：How is lift gener... 阅读全帖 |
|
d*********r
发帖数: 813 | 5 讲得的确非常好。
cruise speed大约0.8Mach, 属于subsonic and transonic aerodynamics,超出low-speed
aerodynamics范围了。飞机起飞着陆阶段属于low-speed aerodynamics。
民用机又和军用机不同（军用机的速度高很多，姿势要求多，甚至需要360度翻转）；
同样是军用机，陆地起飞的战机和母舰起飞的战机也不同（后者起飞距离短，甚至需要
垂直起降）； 同样是军用飞机，subsonic,transonic, supersonic, hypersonic,
high-hypersonic又不一样；同样是一般商用民航机，不同的angle of attack情况也会
不同（随着AoA的增大，气流会与airfoil的上表面分离，出现turbulence甚至
whirlpool）。（当然啦，如果你是一个aerodynimics的专家，你: 会以说，这些本质
都一样，因为都是N-S方程govern的。）
四层意思：（1）飞机怎么能飞起来？（takeoff）（2）飞机在天上巡航，为什么不掉
下来（cruise)？（3）... 阅读全帖 |
|
D****R
发帖数: 6053 | 6 解释的好！
民用机又和军用机不同（军用机的速度高很多，姿势要求多，甚至需要360度翻转）；
同样是军用机，陆地起飞的战机和母舰起飞的战机也不同（后者起飞距离短，甚至需要
垂直起降）； 同样是军用飞机，subsonic,transonic, supersonic, hypersonic,
high-hypersonic又不一样；同样是一般商用民航机，不同的angle of attack情况也会
不同（随着AoA的增大，气流会与airfoil的上表面分离，出现turbulence甚至
whirlpool）。（当然啦，如果你是一个aerodynimics的专家，你: 会以说，这些本质
都一样，因为都是N-S方程govern的。）
四层意思：（1）飞机怎么能飞起来？（takeoff）（2）飞机在天上巡航，为什么不掉
下来（cruise)？（3）飞机如何调整高度和转向（flight control)?(4)飞机如何降落
（landing）？估计这些都不是楼主的意思。楼主要问的是：How is lift generated?
对于这个问题的解释不是没有，而是很多，当然也有一些不完整（如airfl... 阅读全帖 |
|
i*****e
发帖数: 1359 | 7 赞，原来我不懂kutta condition，现在了解了
民用机又和军用机不同（军用机的速度高很多，姿势要求多，甚至需要360度翻转）；
同样是军用机，陆地起飞的战机和母舰起飞的战机也不同（后者起飞距离短，甚至需要
垂直起降）； 同样是军用飞机，subsonic,transonic, supersonic, hypersonic,
high-hypersonic又不一样；同样是一般商用民航机，不同的angle of attack情况也会
不同（随着AoA的增大，气流会与airfoil的上表面分离，出现turbulence甚至
whirlpool）。（当然啦，如果你是一个aerodynimics的专家，你: 会以说，这些本质
都一样，因为都是N-S方程govern的。）
四层意思：（1）飞机怎么能飞起来？（takeoff）（2）飞机在天上巡航，为什么不掉
下来（cruise)？（3）飞机如何调整高度和转向（flight control)?(4)飞机如何降落
（landing）？估计这些都不是楼主的意思。楼主要问的是：How is lift generated?
对于这个问题的解释不是没... 阅读全帖 |
|
c****e
发帖数: 2127 | 8 of
attack都不大。飞机的cruise speed大约0.8Mach, 属于low-speed aerodynamics。由于
airfoil trailing edge的设计是sharp-cornered的，加上气体有黏滞性，这保证了
airfoil在posotive AoA情况下运动时，气流平滑地离开trailing edge并且上下表面没
有压
~~~~~~~~~~~~
力差（即starting vorticity is shed into wake或者说starting vortex is cast
~~~~
off），即满足了Kutta条件，从而产生环流, 进而产生lift。
请问这个没有压力差是指哪个部位？trailing edge?
用机又和军用机不同（军用机的速度高很多，姿势要求多，甚至需要360度翻转）； 同
样是军用
机，陆地起飞的战机和母舰起飞的战机也不同（后者起飞距离短，甚至需要垂直起降）
； 同样是军
用飞机，subsonic,trans... 阅读全帖 |
|
c****e
发帖数: 2127 | 9 supersonic飞行原理完全不一样
靠的是shock wave之后的压力差 |
|
t****n
发帖数: 1347 | 10
Does not a supersonic plane have to take off in sub-sonic speed first? |
|
l*******G
发帖数: 1191 | 11 http://www.ldolphin.org/gspeed.html
Faster than the Speed of Light?
Lambert Dolphin, Physicist
Superman was able to leap tall buildings in a single bound, he was more
powerful than a locomotive, and was said to be able to travel faster than a
speeding bullet.
The speed of a bullet (300-900 m/sec) is no big deal in these days of
supersonic aircraft and spacecraft. Yet our fastest space vehicles do no
better than one one-hundred thousandth (1:10-5) of the current speed of
light. Overcoming gravity... 阅读全帖 |
|
g*****h
发帖数: 15 | 12 Area 51: An Uncensored History of America's Top Secret Military Base [
Unabridged]
Publisher: Hachette Audio | ISBN: 1609410890 | 2011 | MP3 64kbps | 495MB
It is the most famous military installation in the world. And it doesn't
exist. Located a mere seventy-five miles outside of Las Vegas in Nevada's
desert, the base has never been acknowledged by the U.S. government-but Area
51 has captivated imaginations for decades.
Area 51: An Uncensored History of America's Top Secret Military Base [
Unabr... 阅读全帖 |
|
m*********k
发帖数: 10521 | 13 [USTB]
[USTB]10379 m befast Dec 24 ● 本版主上任迎新年节日包子都请排此
[board]60109 m befast Nov 11 ● 申请USTB斑竹
成功奖励 10 伪币的用户: DVI, TheGetty, zhumulangma, sesesese, Ni5, piparas,
mitbbsFBI, NWWolf, XXXOOO123, huntsman, wine999, zkjeffrey, aplets, Songp,
Chargers, hualavender, Novotel, miluo, xinmajia2015, wh, KumGo, woa, chenjiu
, Walkonsnow, jaff1973, kx, jessican, ZhenZhi, Gluc, liuruju, peopleocean,
nn2, peoplehill, SDer, seattle2009, QUINN, matrixmaze, wobest, lxinzheng,
strui, jiawa, dipsy, coo... 阅读全帖 |
|
s*****y
发帖数: 752 | 14 Covidien recruits supersonics research scientist, this is what I know |
|
s*****y
发帖数: 752 | 15 Covidien recruits supersonics research scientist, this is what I know |
|
z*******n
发帖数: 1034 | 16 BY Richard Lawler @Rjcc May 30th 2014, at 7:04:00 pm ET 70
Celebrities At The Los Angeles Clippers Game
The papers are signed and the deal is done (pending approval by the NBA's
Board of Governors). Former Microsoft CEO Steve Ballmer really is buying the
LA Clippers (you can say LA Clippys, once) for $2 billion, now that the NBA
, owner Donald Sterling's wife Shelly Sterling and the Sterling Family trust
have resolved their dispute. Donald Sterling announced earlier today that
he's filing a $1 b... 阅读全帖 |
|
C******g
发帖数: 2930 | 17 Updates
* Ratchet & Clank Future: Quest for Booty Price Drop (now $9.99)
* Supersonic Acrobatic Rocket-Powered Battle Cars Price Drop (now $4.99)
Playable Content
* Mushroom Wars ($9.99)
* .detuned ($2.99)
* BUZZ! Junior: Monster Rally ($4.99)
* topatoi: The Great Tree Story ($9.99)
* Tomb Raider: The Last Revelation (PSone Classic) ($5.99)
* NBA 2K10 Demo
Add-on Content
* BUZZ! Question Pack: Space ($5.99)
* Hot Shots Golf: Out of Bounds Costume Pack + PS |
|
C******g
发帖数: 2930 | 18 Sales and Price Drops
* Sale: Prince of Persia Classic ($4.99; regular $9.99); offer good
through Monday, May 31
* Sale: Supersonic Acrobatic Rocket Powered Battle Cars: Battleball
Arena ($4.99; regular $9.99)
* Sale: Wakeboarding HD ($7.49; regular $14.99)
* Permanent Price Drop: Heracles Chariot Racing - Permanent Price Drop (
$2.99; original price $4.99)
Downloadable Games
* Soldner-X 2: Final Prototype ($12.99)
* Super Stacker ($9.99)
PS1 Classics
* Delta Force Ur |
|
C******g
发帖数: 2930 | 19 Special Offers
Until June 9:
* Supersonic Acrobatic Rocket Powered Battles Cars (was – £7.99/&#
8364;9.99 now – £3.99/€4.99)
* Section 8 (was – £19.99/€24.99 now – £8.69/€10
.99)
* Greed Corp (was – £7.99/€9.99 now – £4.79/€5.
99)
* LocoRoco Cocorrecho! (was – £2.39/€2.99 now – £1.19/
€1.49)
* Ferrari Challenge Pack (NÜRBURGRING, 599GTB, ENZO, 430 SCUDERIA,
612 SESSANTA, F330 P4) (was – |
|
p*********e
发帖数: 32207 | 20 现在做的这个公司，叫boom supersonic
官网：
https://boomsupersonic.com/
看首页合成图，23个客窗，按一排4人宽敞点布置总有50人以上，那应该还是目标在航线
根据网页claim，目标是做到2.2马赫巡航
然后票价 纽约到伦敦3小时15分钟，单程2500usd
三藩到东京五个半小时，3250usd单程
悉尼到洛杉矶6小时45分钟，3500usd单程
而且能飞悉尼到洛杉矶的话意味着北京洛杉矶或者上海洛杉矶也能飞了
我觉得按这个定位，做出来是有不少市场的。
个人感觉，最近十年的大趋势，是服务类奢侈消费增长明显
全球化以来富裕人群的大小和财富总量都在加速扩张
而新一代富人的趋势是减小炫耀性消费而为真实提升生活体验和质量付款
这个飞机这个定价和解决的问题，绝对有很多人肯掏钱。 |
|
w*******y
发帖数: 60932 | 21 GamoWhisper Deluxe Air Rifle Combo
-the following is from the description.
One of the quietest air rifles you can buy
Zips .177-caliber pellets up to 1,200 fps.
Adjustable trigger
Includes 3-9x40mm w/duplex reticle scope and mount
This sharp-looking, sharpshooting air rifle incorporates state-of-the-art
muzzle porting and noise-baffling technology to make it one of the quietest
air rifles you can buy. A spring piston break-barrel action zips .177-
caliber PBA Raptor pellets along at 1,200 fps. (... 阅读全帖 |
|
|
|
|
w*******y
发帖数: 60932 | 25 from Frys ad scan:
for Sat, hopefully online too.
|
|
|
w*******y
发帖数: 60932 | 27 Just logged on to Playstation Plus (PS+) and noticed some more freebies, in
addition to The Simpsons Arcade Game and Final Fantasy V that has already
been mentioned.
Far Cry 2
Fatal Inertia
Mahjong Tales: Ancient Wisdom and Booster Pack
Inferno Pool
Supersonic Acrobatic Rocket-Powered Battle-Cars
|
|
m*****i
发帖数: 2182 | 28 西部联盟：
1、菲尼克斯太阳（Phoenix Suns）：球队建于1968年，菲尼克斯是亚利桑那州的首府
，位于美国西海岸的沙漠中，年降水量稀少，阳光充足，以“太阳”为队名最有代表意
义。Sonic Underwater Navigation System 声纳水下导航系统
2、圣安东尼奥马刺（San Antonio Spurs）：NBA的创始球队之一，最早时球队大本营
在达拉斯，队名为“达拉斯橡木队”，1970年更名为“得克萨斯橡木队”，1973年移师
圣安东尼奥后改名为“马刺队”。“马刺”是骑马者钉在鞋后跟上的一种铁制的刺马针
，以此为队名，可以反映出美国西部大开发的时代特征。Space Power Unit Reactor宇
宙飞行电源装置用的反应堆
3、西雅图超音速（Seattle Supersonics）：球队诞生在西雅图，是世界上最大的飞机
制造商波音公司的总部所在地。1967年球队建立的时候，波音公司正在开发制造超音速
客机，而在波音公司帮助下创立的球队也选择了“超音速”这个名字。
4、达拉斯小牛（Dallas Mavericks）：1980年3月，球队老板在征集来的大约 |
|
n****e
发帖数: 1677 | 29 11/17 11:32
THE NEWS
Backup point guard Earl Watson met withi Sonics coach Bob Hill on Thursday
to discuss his decreasing role with the team. "I just explained to him that
your bench is just is as important as your starters if you are going to win,
" Hill told the Seattle News Tribune.
Our View
Watson is averaging 20 minutes per game this season, but more importantly,
his shooting percentages (32 percent from the field, 22 percent from three-
point land) have been terrible. Coupled with the bril |
|
|
d**l
发帖数: 73 | 31 Sorry, my bad. By the way, how to use long title for posting.
Close in weapon system ( Any good translation in Chinese?)
Anti-Ship Missle Defense (??)
also
your
this
1B
have
trouble
SS-N-22
supersonic
Coyote)
gun-based
warhead
test
at 8m
only
the
target
the
hotter
Fired
to |
|
d**l
发帖数: 73 | 32 ESSM is replacing Phalanx on the lastest DDG-91. Maybe RAM is a drop-in
replacement for Phalanx on the older ships. However, Phalanx 1B upgrade was
reported quite capable against supersonic targets. Does RAM have other
customers other than Germany? |
|
