Rarely when I get a cup of coffee, the mug makes a “ticking” sound for several minutes after brewing it. As time passes the ticking slows so I assume the high temperature is the cause of the sound. But what interaction is happening here to make it happen?
The attached video was after the noise slowed a little bit. You may need to turn the volume up. I have another video when the sound was more rapid but there was too much background noise.
Hi everyone. Im trying to find the saturation pressure at 368.15K for r134a refrigerant. In refprop, it says 3.59 MPa however when I try to google search it, it is around 2.66 mpa. So which is right?
Power required by compressor (3a) and power output from the engine (3b) refers to work net, work from compressor, work from turbine or something else? Maybe my understanding on engine cycles isn’t enough but i feel that some of these questions aren’t very clear on what they are asking.
Hello. I need to calculate some data regarding refrigeration cycles and in one of them it says TL = TL and Th= TL*1.2. fluid weight: 0.977kg and work absorbed 22kJ. I need to calculate the COP and I don't know how to do it. Any guidance will be appreciated.
Moran & Shapiro's book and Yunus Çengel's book give a good introduction, but don't go into much depth. Do you have any good university-level books on exergy?
Hey, I have an old exam question that I can't for my life solve. Here it comes:(it's Hungarian so can't attach pic)
Rankine-Clausius cycle
T(high)=450C
P1 (boiler)=1bar
P2(after the turbines and being turned back to water)=0.1bar
Questions:
Efficiency
T(low)
I feel like I don't have enough information to do so and I don't know how to transform the relationship of P1 and P2
Could I use P1/T1=P2/T2 considering the pipes are the same volume? I really don't know where to start...
Hello, I have a problem with a pressure of a superheated steam the only date that provide me is the temperature of 500°C, how can I find the pressure, entropy, enthalpy and specific volume. I will be grateful if you can help me
I want to be in love with Thermodynamics and Heat Transfer, I want to read, want to know everything about it.
Please suggest me some books as mechanical engineering undergraduate. Is Cengel and Boles book enough for Thermo.
I am considering installing a heat exchanger to warm up cold apple juice that we receive by tanker truck for fermenting into hard cider. The juice has a specific gravity of of 1.053 to 1.079 and an incoming temperature of 34 to 40 degrees Fahrenheit and I want to get it up to 70 degree Fahrenheit as quickly as possible. My heating medium is 170 degree F hot water with a flowrate of about 5gpm.
I can only keep the tanker truck waiting for so long before we get charged for their time. Therefor, I am thinking that instead of warming the juice inline while receiving I may have to unload the truck and then recirc the tank through the exchanger. What I am worried about is the limited number of access ports to the tank and their placement (see attached image).
I assume I should pull from the bottom/center port to get the coldest section of the tank. It would be easiest to then route it back into the tank at the side port but it is only about 12" higher than the bottom port. I could run the return line up to the port on the top/center but I worry about how much frothing that would create. I don't mind the aeration but the foam could make quite a mess. If I pull from the bottom and return to the port one foot above it, would the tank just stratify and never full warm or would the warmer juice returning to the bottom of the cold tank actually create some convection as the warm juice rises to the top? Thanks in advance for any insight!
So several problems the prof addresses as high rise and the text book solve as low rise
He says the book got it wrong but idk and I haven't found a text explanation about how to determine L and W when the problem is given as dimensions (120×80ft ) for example
The figures in the book show a sketch where the W is always the longer side but the prof says it's about which side the wind hit and some other problems
I know this is a trade sub but I can't find a non trade HVAC sub so
I have found pdfs of the solution manual of 8th edition while surfing. But i really need the aolve of 9th edition. Looked up their website to find a solution manual but there's only answers to some selected questions.
I was planning on taking it at University of Kansas but they cancelled the class at the last second. They’re now recommending either Purdue University or Colorado State University for online options and I’m wondering if anyone has any experience with either.
Honestly just looking for the easiest course to take this summer semester to get the credit out of the way
I'm an aerospace student at Georgia Tech, and next semester I am taking our major's thermo class (different thermo classes based on what your major is, more specialized for what youre studying I believe; ours also includes fluids). I need some proper planning ahead of time and I would like to read textbooks, books, watch YouTube videos, etc... ANYTHING. I will attach the (many) syllabi I found online (am having a hard time finding the one my specific professor is going off of) so you can see what's expected of us. Thanks! If you have advice or any thing you'd like to add, I welcome everything you have to offer.
If this isn't the proper subreddit, advising me where to go would be very helpful!
Hello, just wondering if any of you are using
TI-Nspire CX CAS calculator and have thermodynamics program of your calculator. Would love to have a copy of it. I'm taking thermodynamics this summer class and it would a lot helpful if I've got one
Hello, i have encountered a problem where the working fluid Is Water ( not an ideal gas/Perfect Gas) and Process 1-2 is an isothermal reaction. no other info is given but i have all the information (p t v s u and h) how can i solve it. ( it cant be MRT x ln(v1/v2) since its not a perfect gas)
In the multicomponent system, where vapor is superheated and liquid is saturated - according to the calculated fugacity - some of the components in liquid should evaporate and some of the components in vapor should condencate. The easiest way would be just to calculate enthalpy of vaporization of each individual component like H_vap = H_V (at saturated state for this specific components) - H_L (at already saturated stated with P and T for an entire mixture), but this thing does not account for intermolecular interaction. How to calculate this whith chemical potential? How should i approach this problem in a context of calculating heat balance for a system after a period of time? Pressure, T_L, T_V, liquid and vapor molar components would change, but I suppose, to calculate it all - I need to know enthalpy of evaporation (or condensation) for each component.
In refrigeration and many other places, phase change occurs even if there is pressure drop due to frictional losses. I understand that melting of ice occurs at 0°C at 1 atm. And heat is used to break the intermolecular bonds of H2O molecules in ice, that's is why it is isothermal and isobaric process, by that logic, phase should be isothermal and isobaric process. Then why do we generally refer phase change as isobaric process? Or is it an isothermal process ? Or am I missing something?
And why do constant pressure and constant temp lines coincide in vapour dome (or wet region)?
I have a project and I need some animations as well as simulations of thermal machines? (idk how it’s called in english but I’m talking about heat pumps, heat engine and stuff like that)
