m******n
发帖数: 37 | 1 Who knows the rank of Fire Protection Engineering in USA?
Thanks a lot!!! |
j**a
发帖数: 11 | 2 A plastic bottle is filled with some hot liquid (water) and closed. When the
liquid is cooled down, some vacuum is induced due to the air being trapped in
the bottle. This will cause the buckling of the bottle. How to find the
temperature change of the air being trapped? And how to find the bulking? |
s*i
发帖数: 5025 | 3 Thermlcouple，能搞定温度变化。
the
in |
t*n
发帖数: 14458 | 4 你的条件给得不足，如果是最终达到平衡，当然跟环境温度（或者液体）一样
【在 j**a 的大作中提到】
: A plastic bottle is filled with some hot liquid (water) and closed. When the
: liquid is cooled down, some vacuum is induced due to the air being trapped in
: the bottle. This will cause the buckling of the bottle. How to find the
: temperature change of the air being trapped? And how to find the bulking?
|
j**a
发帖数: 11 | 5 Yes, the ultimate temperature is the ambient temperature, say 20 degrees. I
want to find out by the time the cap is closed, what is the temperature of the
air being trapped. For instance, put some hot water of 80 degrees into the
bottle and close the cap, what is the temperature of the air when the cap is
closed? I also want to find out the change of temperature with time. So this
is a transient heat transfer problem. I am not sure how to model the air
being trapped by using commercial pack
【在 t*n 的大作中提到】
: 你的条件给得不足，如果是最终达到平衡，当然跟环境温度（或者液体）一样
|
l**o
发帖数: 1240 | 6 not to easy since it's hard to gather around all the needed BC's data reference
you can first run some temperature measurements to calibrate your model
【在 j**a 的大作中提到】
: Yes, the ultimate temperature is the ambient temperature, say 20 degrees. I
: want to find out by the time the cap is closed, what is the temperature of the
: air being trapped. For instance, put some hot water of 80 degrees into the
: bottle and close the cap, what is the temperature of the air when the cap is
: closed? I also want to find out the change of temperature with time. So this
: is a transient heat transfer problem. I am not sure how to model the air
: being trapped by using commercial pack
|
t*n
发帖数: 14458 | 7 不知道你的被trap的气体温度指什么？如果假设trap的气体内部温度是均匀的
（在内部飞快地达到平衡），这个问题要考虑这些东西：气体和液体之间的对
流换热，气体和瓶子外边的对流和辐射换热（如果不考虑瓶子被加热，如果考虑
瓶子被加热要算算瓶子给加热了多少），体积变化过程中大气对气体做的功（你
的瓶子好象瘪了是罢）
这三个东西都不难算，这样气体的内能变化就知道了，随之每一时刻的温度
就知道了。关键得那些各种乱七八糟的系数得选对数值。
【在 j**a 的大作中提到】
: Yes, the ultimate temperature is the ambient temperature, say 20 degrees. I
: want to find out by the time the cap is closed, what is the temperature of the
: air being trapped. For instance, put some hot water of 80 degrees into the
: bottle and close the cap, what is the temperature of the air when the cap is
: closed? I also want to find out the change of temperature with time. So this
: is a transient heat transfer problem. I am not sure how to model the air
: being trapped by using commercial pack
|
s*i
发帖数: 5025 | 8 Pressure sensor+thermocouple
Why waste time on simulation?
I
the
the
is
this
【在 t*n 的大作中提到】
: 不知道你的被trap的气体温度指什么？如果假设trap的气体内部温度是均匀的
: （在内部飞快地达到平衡），这个问题要考虑这些东西：气体和液体之间的对
: 流换热，气体和瓶子外边的对流和辐射换热（如果不考虑瓶子被加热，如果考虑
: 瓶子被加热要算算瓶子给加热了多少），体积变化过程中大气对气体做的功（你
: 的瓶子好象瘪了是罢）
: 这三个东西都不难算，这样气体的内能变化就知道了，随之每一时刻的温度
: 就知道了。关键得那些各种乱七八糟的系数得选对数值。
|
l**o
发帖数: 1240 | 9 he wants to find the mechanism of bulking
temp and presure is not the final goal
【在 s*i 的大作中提到】
: Pressure sensor+thermocouple
: Why waste time on simulation?
:
: I
: the
: the
: is
: this
|
t*n
发帖数: 14458 | 10
because this is so looooooooooow-tech
hohohohoho
【在 s*i 的大作中提到】
: Pressure sensor+thermocouple
: Why waste time on simulation?
:
: I
: the
: the
: is
: this
|
h****l
发帖数: 7290 | 11 then what is hiiiiiii tech?
【在 t*n 的大作中提到】
:
: because this is so looooooooooow-tech
: hohohohoho
|
m***k
发帖数: 35 | 12 Hi-tech is a work can't be done by a guy only with a BS degree
he gotta be able to derive a bunch of equations to figure it out
and 90% people won't understand that
【在 h****l 的大作中提到】
: then what is hiiiiiii tech?
|
h****l
发帖数: 7290 | 13 that's hi-sci, not hi-tech.
【在 m***k 的大作中提到】
: Hi-tech is a work can't be done by a guy only with a BS degree
: he gotta be able to derive a bunch of equations to figure it out
: and 90% people won't understand that
|
s*i
发帖数: 5025 | 14 Yea, we PhDs should consider hi-tech.
The point is, if we use hi-tech, the possibility of getting a good result will
be slim. Thus the boss will try to add more money to the project, which can
only result further futile tries. But our job will be secured because we are
the only people know how to get involved in this hi-tech stuff :)
If we use low-tech to solve a problem very fast, the project is over.
Consequently, we will be laid-off. :)
【在 t*n 的大作中提到】
:
: because this is so looooooooooow-tech
: hohohohoho
|
