Recent content by MSM

I did the calculations and I got a characteristic time of about 49 seconds as well, which translates to 244s to reach 99% of the final temperature However, that doesn't agree with what is happening in practice. The fluid is basically a reactant that reacts once exposed to high temperature. In...

What if you treat this problem as a flow in a tube with constant surface heat flux. and set Nu=4.36, calculate h, and then solve for dT/dt. How would this be different ? and are you really going to have order of magnitudes error if you solve it this way? I appreciate your input on all of this

No, the tubes are connected to a pump outside the oven and then the fluid flows inside. I am aware that as the fluid flows you will have a temperature distribution along the tube inside. However, I am only interested in an approximation of the thermal time scale (the approximate time that the...

I am not looking for the temperature profile along the tube. Although, in reality there should be a variation of temperature along the the tube. I am assuming a homogenous temperature distribution in the fluid and just need an approximate time frame for the fluid to reach the final temperature...

Maybe the schematic I drew is not really a good representation, but the tube is long (coiled) and is about few meters. What I want to know is the time required for the fluid in the tubes to reach the oven temperature once it enters the oven. Basically, it is a chemical reagent that reacts once...

I tried the lumped system analysis, but my understanding is that for this method to be valid, Biot Number (Bi) has to be less than 0.1 (Bi<0.1). Now consider a liquid fluid with thermal conductivity k=0.14 W/m K, and heat capacity Cp= 2500 J/kg K, and density of 780 kg/m3. Now for long pipes...

I tried the lumped system analysis, but my understanding is that for this method to be valid, Biot Number (Bi) has to be less than 0.1 (Bi<0.1). Now consider a fluid with thermal conductivity k=0.14 W/m K, and heat capacity Cp= 2500 J/kg K, and density of 780 kg/m3. Now for long pipes, Nu=3.68...

So if I have a tubular reactor for nanoparticle synthesis (PTFE tubes ID:2mm). The tubes are heated in a furnace. liquid Reagents at room temperature are pumped by a syringe pump and directed toward the furnace. The reagents decompose to form nanoparticles once they reach the steady-state...

Hi, I am trying to understand how I can estimate the time it takes for a fluid at room temperature flowing through a thin capillary glass tube (2 mm ID) connected to an oven to reach the equilibrium temperature (oven temperature). Assuming the oven is preheated and the tube inside the oven is...

Basically, I want to determine how many microchannels I can have in parallel to drive a fluid (for now assume water),without the syringe pump stalling. Let's say a syringe pump have a maximum linear force of 50 lbf. and I want to drive the fluid at 60 ml/hr. So if I have 4 parallel channels...

Greetings, I hope this is the right place to ask. I have been working with modeling of thermal conductance, G [W/K] of semi-conductor nanowires as a function of temperature. To start, thermal conductivity of a nanowire is modeled using BTE (Boltzmann Transport Equation). Then the conductance...