I recall something similar to this question from a Thermodynamics homework assignment back in the day. Gas flowing in a tube will gain heat from frictiom causing it to accelerate until it reaches mach 1. At that point it will shock and return to subsonic flow. The abrupt jump is defined by...
A couple things occur to me. First, the temperature will be low enough that thermal conduction, not radiation will be the main mechanism of heat loss. No problem with reflective foil like mylar but the impact will be small. If you really like shiny stuff, I would avoid aluminum foil due to...
Having gone through a good part of December in the hospital with pneumonia, I am aware that there is something missing from what has been said. I had viral pneumonia and was treated for bacterial pneumonia and released. I was back three days later for another week and they sorted out that it...
That article seems to support the problem. It measured production rates as lower than previously thought but does not pose that the ratio of C14 to C12 remains constant or that production rates have changed. It states that C14 production from nuclear testing masked natural production. If...
When I read about carbon sinks and the production of CO2, I am puzzled by the trust we have in carbon dating. If I understand correctly, C14 is produced by cosmic rays and nitrogen and is considered a very steady process thus carbon dating is trusted. But if C14 is brought into biological...
You might consider a rolling seal diaphragm. Since you are working with water, you are not at extreme temperatures or pressures. The rolling sleeve type diaphragm has no force between the wall and the piston so sliding friction will be very very low. The force required to roll the sleeve or...
If you are thinking about pressure and what steam temperature you might have, don't forget that you are talking gauge pressure, not absolute pressure. With no weight the pressure is atmospheric (14.69 psi at sea level) and if you double the weight from 1.5 to 3, the pressure increases from...
There is a course on EdX titled "The Challenge of Global Poverty" that presents the results of an evidence based study on tracking. It found in India that tracking produced an overall gain. The better students went further and the weaker students went further. They suggested that the good...
In a convergent, divergent nozzle, I think the limit might be imposed by the back pressure of the atmosphere causing the shock to form inside the nozzle. I am not an expert on the thermo involved in the calculations and so I don't feel qualified to take the argument much further than that. Any...
Thanks for the additional links. The third one was informative as it offers the effect is exponential. There are a variety of articles found on google scholar that deal with the topic but none give an empirical correlation that should apply to a horizontal tube and shell heat exchanger. I am...
I wish I could. The mathematical model needs to calculate a water out temperature from the equation that says the Q calculated by the U value, area, and log mean temperature difference is equal to the Q gained by the water from flow rate, heat capacity and delta T. Since T out is inside a log...
I am working on a model for predicting cooling in a system that evacuates a vessel and cools by evaporation of water and the water vapor is condensed in a tube and shell heat exchanger. My concern is the prediction of the steam side heat transfer coefficient as the air is removed from the...
I am a semi retired Chem E. with an interest in learning all the time. My strengths a.re probably in industrial grade heat transfer and a background in sugar production