1. benit13

    Cooling tower models

    As mentioned in another thread, here's some research I've been doing on cooling towers which might come in handy when working out evaporation ratess. The method below uses the effectiveness of a counterflow heat exchanger; for a more straightforward scenario, try using the effectiveness for a...
  2. E

    A mathematical model for natural cooling of a cup of tea/coffee/ etc.

    hello I have some problem modeling an approximate model of natural cooling of a cup of tea/coffee left in a closed and controlled room. I attached a detailed PDF document (called 01.10.19) that describes all the details regarding the questions I am going to ask below. 1st questions...
  3. O

    Electricity free Air cooling ???

    There are a few videos on Youtube of people installing what they believe to be AC units ... It consists of a bank of cut off water bottles large diameter outside , a breeze enters the the bottle , exits through the narrow top inside the house at higher speed , they claim this reduces the...
  4. C

    Help - Oil Liquid Into Solid In Rising And Cooling Water Column

    Hello, I am trying figure out a fast and simple way to create 10mm spherical balls of cocoa butter in a production line type environment. I want to avoid the time it takes to pour the mass into molds, cool them, and then have to remove them. I have an idea and would appreciate feedback and...
  5. J

    Cooling without heat

    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...
  6. R

    Constant volume cooling

    Hello everyone, I solved a question but having no answer sheet I am not completely sure if what I did is correct. Problem: 5 kg of CO2 at its critical state is placed in a perfectly rigid container, which is then cooled until the temperature is 260 K. - What is the volume occupied by liquid...
  7. J

    Cooling system for LED Panel

    Hi Guys, For a DIY project, I am trying to design a cooling system for a 2400W LED panel that I have built by using copper tubing and a chiller/pump system. So far, I have calculated that the Tout of the water leaving the piping CANNOT exceed 19 deg C but I have no idea how to calculate...
  8. G

    Problem in adiabatic expansion and cooling

    Hey guys. I have a problem in adiabatic cooling and expansion and there is something I didn't understand. when we are compressing air without transfering heat(so adiabatically), why does the air heat? As I know, because of moving "wall". when molecules heat on moving wall kind of baseball bat...
  9. W

    Design an Experiment

    Can someone give me an idea for a relatively simple experiment to do with water cooling. Maybe to do with the color of the container, or adding a substance to the water. Thanks
  10. M

    conversion/relationship: Thermal conductivity (k) to Newtons Law of Cooling (k)

    Is there a conversion factor from the specific substance (k) value in Q/t = -kA (T2-T1)/L thermal conductivity, in units, cal/sec/m Kelvin. To the (k) value in Newtons Law of Cooling dT/dt = -k (T object - T surroundings ) or can the (k) in the cooling solution, T(t) = T surr + (T obj - T surr...
  11. W

    Newton's Law of Cooling

    I have a question: A body with temperature T_{0}above that of it's surroundings is allowed to cool. The rate at which the body cools is proportional to the difference between it's temperature and the temperature of the surroundings. a. Derive an expression for temperature above the body as...