What is Cooling: Definition and 638 Discussions

Hello, I understand how evaporation contributes significantly to heat loss through the loss of KE from the vibrating water particles on the skin; However, what about the sweat droplets that come off of a person. This water has Kinetic Energy and is now being displaced from the body(the...

Evaporative cooling is pretty cold, but I wonder how effective the following would be at chilling the air even further, even if not very energy efficient with having to freeze ice, additional air pump, etc. I was thinking that since the air in the air chamber was cooled, the ice would melt at a...

Hi. I just read an article where following cooling method is described. Apparently it's very common, but I don't know what it's called: A gas under pressure is released into a vacuum through a small hole. The average particle speed in this beam of gas is the same as before, but the...

Is there any minimum value of cooling water temperature for a particular system? In our plant cooling water temperature is much below the normal operating range.

Hi everyone! I was wondering if there is a known equation to calculate how the speed of a fan affects the cooling of a heat source. Is there a way to calculate this or know what type of relationship it is? Thanks!

Hi all, If I have a hot object in space (not a star but say an oven or just a hot gas as would be on Earth < 10,000 degrees Kelvin) glowing at a temperature T and I want to know long it takes to come to equilibrium with the vacuum of space around it, how can I calculate such a time? I could...

Hi, I am designing a system to cool aluminium through contact cooling. I have a steel die with 9x 20mm diameter cooling chambers. Water is pumped through the chambers which cools the steel die and hopefully the aluminium sitting on top of it. I am looking to find the temperature of the...

Homework Statement I want a detailed understanding of the temperature drop of a boiler when water is lost from a leak. I have a temperature recording of a leak that lasted for an hour and caused the temperature to drop from 170oC to 150oC when 2.55m3 of water was lost. I have tried using steam...

I 90% understand the question and solution but unfortunately I have some hesitations about the formal solution in the book. First of all, when calculating P4-P3, choosing lines and points on them, why do book assume velocities of 3 and 4 to be the same...

Homework Statement You come across a dead body at 3 PM. Its temperature is 83.6 F. 30 minutes later its temperature is 78.6 F. How long was the guy dead before you found him? Homework Equations ##\frac{dT}{dt}=-k(T-Tair)## T(0) = 83.6 F T(0.5) = 78.6 F The Attempt at a Solution This is a...

We have an STG based thermal power plant in our hand and the steam flow rate is around 10 kg/sec or 36000 kg/hr. The Condenser is kept at 10 kPa pressure and the temperature there is 45°C. Now, a cooling system of capacity 142 ton of ice has been applied to the Condenser. I don't want to give...

Hey Guys ! what is the main difference between Heat Exchanger and Cooling Towers?

ok, we have a really efficient way to make heat (adding energy into a system) all we have to do is pass a current through a high resistance wire, boom, close to %100 heat generation. however, from what I can tell there is no way to create coolness (take energy away from a system) like that. we...

I was wondering all the assumptions I need to make regarding a design for a heat exchanger and cooling tower design from a IC engine testbed. Each engines average output is 55kW and the water jacket temperature is 80 degrees (C) and has to be cooled to 65 degrees (C). The ambient atmospheric...

A cup of tea is removed from the fridge and left on a desk. The temperature of the room is constantly E and T(t) represents the temperature of the tea after t minutes. dT/dt = K(E-T) Z(t) = E-T(t) How do I find the general form of Z and T?

Can we find the natural frequency of water's molecules by using of Newton's law of cooling and resonance phenomena?

Hi, I know and understand that heating a system causes the particles inside to increase in kinetic energy, due to the conservation of energy. What I don't understand is how does cooling a system causes the kinetic energy of the particles to slow down. Like how does cooling from sources such as...

Single fan is enough for 6800K? like Thermaltake CLW0222-B Liquid CPU Fan or Cooler Master SEIDON 120V Plus Liquid CPU Cooling Fan. I want a ans which better for me 2 fan cooler or single fan cooler? note: My PC should be RUN minimum 14h/day

I've been tasked to see if I could determine the number of chill rollers needed to cool down glue being extruded onto a fabric. I'm not sure if my method is valid. The roller has wall thickness d with contact area A. Water inside chill roller is at T1 and glue is at T2. 1) Calculate the rate...

Is to possible to provide cooling for automobiles using vapor absorption compression system utilizing the exhaust gases? If possible how efficient can this method work?

I have a glass vessel with a cooling jacket which previously had cold water running through it. However now it is disconnected from the pump and the jacket is empty, and there is condensation in the jacket from the little water that was left in there. How can I get rid of this condensation...

Just Qualitative Analysis: There are many ways of cooling a coffee cup. But here I want to understand about concept of fins. So I am using a spoon to enhance the heat transfer rate. Put the spoon vertically in the cup. We have two ways to put the spoon, other one is upside down. I am curious to...

hello everybody! As an undergraduated student of engineering I have to design a elecric car radiator from the beginning! The truth is that am a little confused.. I started my calculations by estimate the rate of heat transferred by the drivetrain and finding the maximum delta T needed.. any idea...

I have a project which i need to cool down certain quantity of hot water. I need to cool down water of around 25 litres at 50 Degree celcius to 30 Degree celcius, Static water, not flowing. (or incoming 50 Degrees - Outgoing 30 Degrees with approx 1.5 gallons per minute flow rate) time...

Homework Statement [/B] Calculate the BTU/hr required for water to lower its temperature to find the compressor capacity required - Cool 30 Liters of water from 50 degree Celsius(T1) to 25 Degree Celsius(T2) – ( 122 to 77 Fahrenheit ) -Water in a closed vessel, Static, not flowing. -Max...

Homework Statement If a 5 amp unit can cool 4 cups of water from 75 to 50 degrees fahrenheit in one hour, what temperature could a 30 amp unit cool 128 cups of water in the same amount of time? Is there enough information here to get an idea about what the 30 amp unit would do? If so where...

I have a bit of confusion about a closed container scenario. First, I'll start with the open container. Say water is at some temperature, exposed to low humidity atmosphere, and begins to evaporate. The water that evaporates diffuses never to return to the container. To find the final...

Our 2002 Toyota Sienna's cooling system capacity is 10 quarts (no heater). Using radiator petcock, 5.7 quarts of coolant is drained. Recommended mixture is 50/50 antifreeze and distilled water, which is what it is now before the replacement starts. Drain-1: Refill with distilled water only...

Hi all! I'm analyzing a fermenter and the water cooling system that cools it down. In analyzing this I've found kW and kWh required to cool down the fermenter using Q = dt*cp*m However when I try to find the overall heat transfer coefficient U using the data, I find that it varies with...

Hi guys, I have question regarding cooling towers. I have been asked to check if cooling towers would be efficient and economical to cooling system for a power plant to be installed in Weymouth, England. As per my calculations, heat to be rejected (in the condenser) from the system is 20 MW...

Hi, How can eco-cooler works? The explanation of blowing with mouth are totally wrong, but I am curious aboud dynamic of air flow, if is possible to achieve measurable cooling Thanks

hey guys and gall's i'm builing an amplifier for audio, basically a 6 channel amplifier, each amplifier is a pcb which is mounted on a solid aluminium base and will need to dissipate about 30W. I will mount these upside down under a circular sheat of metal in a " circular" 6-way pattern...

Wet bulb temperature is the lowest thermodynamic temperature of air that can be achieved at ambient condition, by creating 100% relative humidity in the immediate surrounding of the thermometer using cotton wick. As Wikipedia says "By contrast, the dew point is the temperature to which the...

I'm a design draftsman, I have bar of 17-4 stainless steel it weighs 6.9 lbs. The Product Data Sheet shows a specific heat 0.11 (BTU/lb/F (32-212F) (www.aksteel.com) It's at room temperature or 70 degrees F. I want to cool the bar to 50 degrees F. The surface area of the bar is 245 sq. inches...

First of all i must say that i have lack of knowledge about physics. I have this silly idea to spray my metal roof in a humid area. No lack of groundwater and I am intending to sprinkle my metal roof with groundwater during solar peakhours. The roof is total only 30m2. I understand that...

I am currently doing a experimental project work on superconductors. I am supposed to study properties of FeTeSe. I am having trouble understanding the difference between Zero-Field Cooling and Field Cooling. In both cases, I am measuring magnetization with varying temperature (from lower to...

Hi everyone! I have a silver plated copper heat exchanger (with an internal embedded circuit where liquid nitrogen flows) attached to a bigger aluminium block in order to cool it down. First, I want to estimate it's instantaneous cooling power during cool-down to a stable temperature. I have...

When I plot the isenthalpic curves in T-P plane, I see isenthalpic curves are not well defined in the lower temperature region in T-P plane. Inside the inversion curve Joule-Thomson coefficient is positive so gas cools and outside of the inversion curve Joule-Thomson coefficent is negative so...

I have an object that is decently thermally insulated. I want to plot how a constant cooling power of a few watts for a few minutes is going to affect the object's temperature. I need to account for how much heat is leaking in. Getting a constant cooling doesn't seem easy. If I instead use...

Hi everyone, For adibatic quantum computation one prepares the groundstate of a particular Hamiltonian and than adiabatically evolves the system to a problem Hamiltonian Hp which groundstate encodes the desired solution to a satisfiability problem. If the evolution takes place slowly the system...

I am trying to figure out how much ice i need to produce during daytime to cool a bedroom at nighttime. Currently a 9000 BTU Air conditioner with a separate indoor and outdoor unit is more than sufficient. The air conditioning is set to 24 degrees Celsius and the outdoor temperature goes from 32...

Hey everyone :) I am a Tunisian Mechanical engineer student, doing my first practical internship. I need to find a way to cool water, that isn't expensive. I have 'ambient heat' water that comes from an outdoor pool, then it goes to 3 different compressors, in order to cool them, then that...

Old article: http://edition.cnn.com/2009/TECH/science/08/28/hurricanes.gates.gray/ What do you guys think? Where do you see this project going? The official word is that it's not being publicly funded. But if there was even a 10% chance it would work, I see governments lining up at the...

I want to do a little inquiry involving water, and I need to know what the 'cooling down speed' of water is (how much heat a certain volume or surface of water emits per second). Can anyone tell me if there is a unit and/or formula for this?

Hi! I'm a teacher in Mechanical Engineering, and I organize a (yearly) student's project where they design and create a cooling machine. The machine works by compressing air, cooling the compressed air, and then rapidly expanding it. This can lead to temperatures of minus 7 degrees Celsius. I...

I came across an equation used in one of the forums from a few years ago. Found here: https://www.physicsforums.com/threads/calculate-how-long-it-will-take-for-the-ice-to-melt.531908/ I am researching a similar topic into melting ice and using it as a cooling solution. However when i came...

Homework Statement For how long you have to let bottle in a river, if you want to cool a liquid inside from 22 °C to 12 °C, when river is 8 °C? Homework Equations Q=cm(T1-T2), Qc=l*S(T-Triver)/d *t The Attempt at a Solution I know how to solve it for a case when we substitute in equation Qc...

I've created a small liquid cooler and would like to test for it's cooling capacity. The only way I know of doing it is to circulate the coolant into a small reservoir with a heating element and apply power adding heat till the cooling unit is maxed out holding at a predetermined temperature...

So i want to create a container that is part of a system that already actively cools things that touch it. This variable cannot be changed. What i need is a container with some sort of valve that automatically opens up at a certain temperature. Thereby allow air to circulate and reduce the...

Hi, I'm thinking of doing an experiment related to Newton's law of cooling, just a simple heat up a liquid to a temp graph its rate of cooling, repeat for different liquids. I was thinking of seeing if from this graph I could calculate the specific heat capacity of the liquid, but I don't know...