紧急！！有谁会解？？

Air at 40kPa and 250K flows across a 2-m square plate at a velocity of 20m/s. The plate is
maintained at a constant temperature of 350K. Calculate the heat lost by the plate.

根据table, 当P=1atm, T=350K, properties of air如下：
density=0.998kg/m^3, viscosity=2.075x10^5 kg/m.s, kinematic viscosity=20.76x10^6 m^2/s,
thermal conducivity=0.03003 W/m^2.K, Pr=0.697, specific heat capacity= 1.0090 kJ/kg.K

(the values of viscosity, thermal conductivity, specific heat capacity, and Pr are not stongly pressure-dependent and may be used over a fairly wide range of pressures.)

我会先找Re(reynolds no.)
reynold no.= density*velocity*Length/ viscosity
           = density*(20m/s)*(2m)/ (2.075x10^5kb/m.s)

when P=1atm, density=0.998kg/m^3,
可是，现在P=40kPa, density=???

我是过用ideal gas law 来找density--〉density= pressure/ (gas constant*temperature)
可是，想一想，不可能用ideal gas law，也没有其他pressure 的数据来算interpolation
请高人指点，谢谢。。。

Infinite81

我的 thermodynamic 忘到一干二净了... 帮不到...

你整片抄下来没有人会帮你的，我都懒惰看，不如你简洁的list出来就会有人帮你。