Flow Definition and 1000 Threads

Summary:: How to calculate the rate of heat transfer between hot external water and cold internal water in a pipe. The image attached is my attempt at the question however, I find myself stuck trying to work out internal and external heat transfer coefficient.

Covid is surging again due to the Delta Variant. I saw in the news of many oxygen tanks with people connected to them even outside in hospital tents. I'd like to know something. If a person accidentally given more oxygen than required, for example. 4 Liter/Minute instead of 2 Liter/Minute...

Could someone explain the green highlight to me, please?

I don't know where to start with this problem. If ##\pi_a = (\mu + TS) u_a## then show that \begin{align*} u^a \nabla_{a} (\pi_b G^b) = 0 \end{align*}where the field ##G^a## is a symmetry generator. [##S## is entropy/baryon, ##T## is temperature, ##u_a## is a one-form field corresponding to a...

I performed an experiment where I let water flow out of a measuring cylinder through a hole at the base of the measuring cylinder. I let the water run out for 30s, recording the volume after. I did this for different heights of water in the measuring cylinder, and kept the pressure of water at...

how to calculate shear stress using shear flow

I was playing with the Schrodinger equation and realized that it can be interpreted as a flow equation. If we set $$ \psi = A e^{i \theta} $$ We can put the Schrodinger in the form ∂ψ∂t=(−∇ψ)⋅v+iEψ If v=ℏθm and E=ℏ2m(−∇2AA+∇2θ)+ρV I find this intuitive personally as it shows that the...

Suppose we have a charged metal tube through which charged ions of compressible fluid is passing. I want to know whether the boundary layer will still form that will resist the flow or the flow will be smoother. We all know how strong electromagnetic force is and this will push the ions away...

I tried to do a Euler Lagrange equation to our Lagrangian: $$\frac{S_\text{eff}}{T}=\int d^6x\left[(\nabla \phi)^2+(\nabla \sigma)^2+\lambda\sigma (\nabla \phi)^2\right]+\frac{S_{p.p}}{T}$$ and then I would like to solve the equation using perturbation theory when ##Q## or somehow...

There are 70 jets of 1/16" diameter along the tube and I neeed to create flames 1" high. I know the calorific value of natural gas is much less than LPG (39 MJ/m3 Vs 93 MJ/m3) . I am not sure what assumptions to make from there in order to compare the predicted natural gas to the LPG volume...

I am having a heater installed for my 12ft round above ground puddle pool. The heater is a K-Star K-5 (5kW) heater. The manual says the heater's max flow rate is 8GPM and I'll need to install a diverter with a valve to bypass it until the flow is <8GPM. How do I determine what my current flow...

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...

Hello. I am reading Hibbeler's Mechanics of Materials (ninth edition). Example 7.5 computes shear flow at a segment where there are nails attached to different boards. He chooses a cut like the one shown here: And gets (by symmetry between C and C') the shear flow q computing the first moment...

OK, I have read all the Fanno flow equations, I understand mass and enthalpy conservation for adiabatic flows give the result that friction causes Mach number go to 1... But I cannot think of a physical explanation for the counter-intuitive fact that friction both accelerates and cools the...

Ideas on moving hot air from houseboat to enhance natural flow with additional solar 12v fans. 50 foot pontoon houseboat mobile home style cabin in desert southwest. Boat has windows but takes hours to cool down in evening when outside temp is cooler. working to isolate why cabin stores so much...

Hi there. I would like to start saying that I am not an engineer or scientist, and that my knowledge about vacuum and vacuum systems, in general, is limited, and I would like to apologize in advance if I am not describing the problem accurately. The application I am posing this question about...

Hello: I was reading about thin-walled members under shear force, specifically example 7-7 of Hibbeler's Engineering Mechanics, Mechanics of Materials. First, the fourth Edition: As you can see above. He starts by computing the moment of inertia on the first equation by subtracting a rectangle...

The assignment is to find the optimal operating temperature and maximum product concentration of reactant B, assuming a constant temperature across the PFR length. Please could someone help? thanks the reaction is a series reaction: A → B → C (liquid phase) Here is my current code which is...

Hi what dynamics are moving liquid in open channel flow without slope (irrigation channels)? Are they mostly hydrostatic forces? imagine 2 scenarios 1. Channels are empty and are being filled for the first time. What forces drive the liquid until it becomes big static lake? 2. Channels are...

Above is a picture of a potentiometer with terminals A, B, and W. Does current always from from A to W or can current flow directly from A to B? Is there usually both? And what do they mean when they say a potentiometer is an effective "voltage divider"?

N/A

Yes, heat can flow into a body without increasing the mean kinetic energy of its molecules. Transferring heat energy to an object will raise its internal energy, this will not necessarily cause an increase in temperture. Specific latent heat is the energy required to change the state of one...

I have solved this question and it seemed pretty easy, but I got an extremely large number for the mass flow, I had to post the question here to make sure I did it correctly. Any help will be appreciated.

Hi, I was attempting the following turbo machinery problem and am getting quite stuck on the first part of the question. The question is: A design of an axial flow gas turbine stage is conducted for the following parameters at the mean radius: Stage inlet stagnation conditions: ## p_{01} ##...

Hello, The question will probably be related to mechanical engineering / chemical engineering / aeronautics. I come from the field of optics and have no background at all on fluid dynamics. I'm trying to calculate the dependence of pressure on distance, i.e. P(x) in a gas flow problem: I...

I have been studying the representation of generators in power flow studies and I would appreciate your comments in this thread. From the book Fitzgerald & Kingsley's Electric Machinery, I understand that there are unsaturated and saturated reactances. In section 5.3.2 of the book it is said...

I've come to a grinding halt with this and I can't see a way forward. Can someone please take a look at what I've done so far and let me know if what I have done is OK and then if it is, give me a hint on how to proceed. First up, Is ## u \cdot \nabla \cdot T = u_\alpha...

NOTE: By "ideal", I mean incompressible & inviscid (the forum doesn't allow a long enough title). I was looking at this Wikipedia article, and the graph of this function struck me as looking exactly like ideal fluid flow around an object. https://en.wikipedia.org/wiki/Lambert_W_function...

Hi, I have a valve which is connected to a pipe on both sides. I measure the pressure upstream of the valve. Downstream of the valve is a screw pump. I control my valve using an analog voltage input between 0 and 10 volts. According to the datasheet, the relationship between the analog input...

Hi, I was recently attempting a problem about the height of buffer regions and viscous sublayer. Question: A fluid flows through a smooth pipe of diameter 150 mm with flow rate, density and kinematic viscosity of 0.180 m^{3} s^{-1} and a density 700 kg and 0.40 \times 10^{−6} 𝑚^2...

Hi, I was recently learning about turbulent boundary layers and came across the 'Prandtl mixing length'. I am struggling to understand what the concept is and what its purpose is. I would appreciate any help or guidance of where I can look to gain a better understanding. The information I...

The possible answers are: (I do not know what is the right one) A. ##H=120m## , ##S=0.0131\frac{m^3}{s}## B. ##H=60m## , ##S=0.0231\frac{m^3}{s}## C. ##H=120m## , ##S=0.0231\frac{m^3}{s}## D. ##H=240m## , ##S=0.0231\frac{m^3}{s}## E. ##H=60m## , ##S=0.0131\frac{m^3}{s}## F. ##H=240m## ...

I'm struggling with calculating the flow rate for an oxygen system. There is a pressurised cylinder. This then joins onto a pressure reducer. Then travels down a length of pipe which branches off to 4 exits there is no restrictions on the exits it just goes to atmospheric pressure. I am yet to...

The problem states: Two parallel plates separated by distance h, the plate at the top moves with velocity V, while the one at the bottom remains stationary. My initial approach was: I considered, ##du/dy = V/h## and for the shear stress ##\tau = \mu \frac{\partial u}{\partial y}## For...

trying to calculate the mass flow of Water vapour that is produced within a vacuum of 30 inhg when the water temp is 40 degrees. How is velocity calculated in this scenario. Also what boundary layer does the water vapour have.

in the limit as Re→0 , we can neglect the material derivate of v ( Dv/Dt =0 ) but why in books they always make the gravity effects equal to 0? i can't understand and no one really explains this stuff

I am confuse understanding between unsteady and turbulent flow. If I look the fluid simulation in Youtube, they both look the same. What is the difference between them? Please explain for a beginner.

water flow from a faucet will neck down its radius as it flows to the bottom of the sink. It is asserted that this is due to the fact that gravity increases the velocity of the fluid. This is shown at . I am trying to simulate this, and am not having much luck. shows this for a flat...

I am not sure how to do this at all or what exactly he is asking me. [Mentor Note -- Two threads on the same problem have been merged into one]

Hi, I'm looking to find a very very basic model to calculate the heat transfer coefficient in a tube with given heat power exchanged ##Q##. The fluid inside the tube starts sub-cooled (##T_{in}## is known) but exits the tube with a quality of steam around 0.15 (pressure is supposed constant)...

I have to estimate the Reynolds number of the fluid flowing around a blade but I only have one detail: the length of the blade is 0.66m. I have no idea how to do it and I got to submit the assignment in a week, I am desperate for help here.

Hello all, I'm having trouble figuring out the volumetric flow rate upstream of a relieving pressure regulator used on a 1/4" OD nitrogen line. Upstream of the regulator P=100 PSIG and T=70F, while downstream P=80 PSIG and T=70F with downstream consumption at q=4 L/min or 0.91 SCFM (at std...

Hello good people! I'm studying the compressible flow and the book refers to this example. I can't understand how does it calculate the angle Θu? In the previous example, there is a method to calculate it but it requires all the properties once the fluid is deflected, therefore, that's not the...

This is for a campervan project I am working on, I am trying to take outside air that is cold (Canadian winter) and mix it into the return air in my diesel heater. I need to hit a specific minimal CFM to maintain proper Co2 levels inside and I would like to be able to calculate this. The axial...

My goal is to determine the ideal amount of air flow, in order to keep CO2 below 1000ppm and to minimize heat loss. I calculated the following based off a similar post in this forum, and I am hoping this can be verified so I know that i am in the right ballpark and going in the right direction...

Frankly, i don't even know how to start this. I deducted from the solution, that they must have used power/(specific heat capacity x temperautre), however i don't understand how that will give the rate of flow of air. Could anybody help, please?

As I understand Darcy's law, it computes the flux of water through an area. The same value of flux can be the realized by different combinations of a density of water in the soil and the velocity of that water. So. as far as I can see, Darcy's law is ambiguous about which combination of...

I am looking for help on the following: a) Given the system shown in the figure below, derive the steady flow energy equation from first principle. b) Again using first principles, show how the energy equation would change for the case when the system is unsteady. I am trying to learn this...

So, it's a long way to the solution, but I'm finding it difficult to find a starting point. I'm going to say that as a first step, I should find what the value of the stream function ##\psi## is, at the surface. In order to do this, I need to use the following equation: ##F=\phi+i\psi## If I...

In part c, plotting the vector field shows the vector field is symmetric in x and y in the sets {x=y}. in {x=y}, the variables can be interchanged and the solution becomes x = x°e^t y = y°e^tHowever, these solutions do not work for anywhere except {x=y} and don't satisfy dx/dt = y and dy/dt =...