Flow Definition and 1000 Threads

Homework Statement I'm making a program that draws a graph of the weight of an hourglass. Obviously at first we know the weight, and as the grains begin to fall it decreases by the amount of mass in free fall. However I ran into a problem when the grains begin to hit the bottom. It's impossible...

Here is a gravitational slingshot figure from some homework exercise : ##m_1## is a small mass, say, a space probe, and ##m_s## is Saturn. The direction of ##m_1##'s velocity completely reverse direction due to Saturn's pull. ##m_1## come from very far away and end up very far away as well at...

Homework Statement A horizontal Pitot tube (with one end open for airflow and another closed) is accidentally installed into an airplane askew, so that the tube is not horizontal. Instead the closed tube end is higher (in the y-direction of a xy-plane) than the inlet end. How does this affect...

Hi In this system of water flow, water enters pipe A at x pressure with the aim of pumping it to the house Excess water or rather recycled water is flowing back via pipe B into pipe A Is that possible according to the law of physics i.e. will the pressurised water attempt to flow up into pipe B...

Sir, Kindly let me know how to calculate flow rate (cfm or Litre/m) of air flowing through a pipe of 12 mm dia from a reservoir at pressure 7 kg/cm2 to atmosphere. i.e ;- how much volume of compressed air could pass within a minute through a "X"mm dia pipe from a constant pressure (7 kg/cm2)...

Hi everybody, I am working on a project to design an inspection system in a gravity tunnel. Can anyone advise me if the flow velocity in a partially filled pipe is the same as the flow velocity in a fully filled pipe? Thank you in advance!

Can anyone help on this problem encountered in gas chromatography: Two helium incoming gas lines A and B are connected together via a cross-shaped connector to two outlets C and D. All in and out lines are capillaries with diametre in the 0.1-1 mm range and lengths in the 10s of cm to 10s of...

Homework Statement Imagine that you are blowing air through a straw in a cup of water and the root of the straw was connected through a rectangular box with empty base and every side of the rectangular box was cut into "teeth" shape. Bubbles will come out from the teeth of the rectangular box...

Homework Statement Water flows through a circular pipe with a 180° horizontal elbow and exits to the atmosphere through a nozzle as shown in Fig. Q3. The diameter of the pipe is 300 mm and the diameter of the nozzle exit is 160 mm. The density of water is 999 kg/m3 . The mass flow rate of...

I'm really confused by this question, as it is different than the examples we did in class. I've compared my answer with a few classmates and I'm getting a different one, so I'm not sure if I've done it wrong or if they have. I'd really just like to know if I am on the right track! Thank you :)...

When compressible effects are accounted for, viscosity should vary with temperature. Doesn't this violate the concept of Newtonian fluids, where shear stress is linearly proportional to the strain rate?

Homework Statement When reading about directions of magnetic flux in relation to current flow on pages 6 to 8 of http://www.free-energy-info.tuks.nl/Non-Ferrous-Magnet.pdf , I found that in figure 11 the current is traveling from + to - terminals, while in figure 12, the current flows from - to...

Hello... Can anyone tell me how sine and cosine came in ,above .(To the last of the attachment pic) Thank you.

I have a couple of questions regarding several key areas of fluid mechanics: 1. My first question deals with the Navier-Stokes equations. Does incompressible&irrotational flow imply inviscid flow? My answer is yes and here is my thought process. In the incompressible form of the Navier-stokes...

I tried posting this question in this forum a couple of weeks ago, but didn't get an answer to my question. I'm going to try posting it again using the formatting template so that it is hopefully clearer. I am also not sure if this is the right forum to be posting this in. It is a problem I ran...

Are fluid streamlines in an irrotational, but viscous, flow parallel? Or does the flow need to be both irrotational and inviscid?

Hi, A chamber (manifold type cylinder) has 1 inlet and 8 outlets of 3 inch diameter each. 8 suction blowers are connected to the chamber's outlet. Each blower's suction flow rate is 1000 cfm. what will be the flow rate through the inlet of the chamber (diameter = 3 inches). Will the inlet...

If throttling reduces mass flow rate then how can we say it as steady flow process where the mass flow rate is constant?

Homework Statement At a processing plant, olive oil of density 875 kg/m3 flows in a horizontal section of hose that constricts from a diameter of 2.92 cm to a diameter of 1.20 cm. Assume steady, ideal flow. What is the volume flow rate if the change in pressure between the two sections of hose...

Homework Statement [/B] Find an equation for the flow velocity of a river that is parallel to the bottom as a function of the perpendicular distance from the surface. Apply the boundary conditions given and solve, and find the velocity at the surface. Note that the coordinates are: x is the...

I'm about to attempt this question but beforehand I was hoping if someone could just check if my diagram is correct on the basis of the question; A feed stream contains H2, CO and a trace of CH4. Pure CH3OH is produced by means of a reactor (CO + 2H2→CH3OH), separator and recycle with purge to...

So you can solve the Stokes equation for flow around a sphere to obtain the pressure in the fluid: p=p0-3nuacosθ/2r2 where n is the viscosity, u is the speed of the fluid (along the z axis) far away from the sphere, a is the radius of the sphere and r,θ are the usual spherical polar coordinates...

Angular momentum is conserved in a closed system. Is thermal isolation required too? An example special case in mind is a closed cavity high speed rotation. It contains high pressure gas and the thermal flow is driving convection currents creating turbulence and or a heat pumping loop...

Homework Statement Fluid flows between 2 parallel plates, flow is fully developed and laminar, the distance between the plates is h In the notes there is a general form of solution after integrating it 2 times. where a is h. but i saw in the book that we have to get +h/2 and -h/2 then add...

If we have a source of AC current with two terminals ( A and B ). We connect a device with this source. Now we say that one wire is live and other is neutral. But my question is that, how one wire is neutral. As we say that in AC current the terminals change the polarity. Its mean that some...

I am an electrical guy, i can't understand the concept of constant flow system...and how temperature is controlled in room by Air conditioner...thanks

In the full internal reflection case where we have a refracted evanescent wave, If another object is nearby, then we could have wave tunneling phenomenon(frustrated total internal reflection). 1) So, how can the evanescent wave which does not transfer any net energy produce another wave at the...

A building has a water pipe inlet. I have found that at if I open the valve at this location fully, then I get 180 liters per minute at a residual pressure of 0,2 bars (static pressure is 5,4 bars). Is there a fixed relationship between the flow and pressure drop so that I can easily predict...

Hi All, I'm hoping to work on deriving the governing fluid flow equations for a frisbee in flight theoretically and then to test it on a wind tunnel, and compare results. If u could please help on how do i apply/derive the necessary equations. Respectful Regards

Homework Statement (This isn't homework; someone is insisting that the graph of height of a leaking water column/time is a parabola, which makes no logical sense to me, but I want to prove it) You have a bucket (5 gal) filled to the top with water, and a small hole in the bottom. Find the...

Hi, I'm building an experimental set-up for some heat exchanger I'm trying to analyze, I want to maximize the flow through this little piece. I have a stable temperature bath, (see picture) that has an evacuation valve on the bottom. I only took introduction to Fluid Dynamics (found it amazing...

I am going to presenting on a scientific report and the report that I choose (this can still change) is the following: http://onlinelibrary.wiley.com/doi/10.1029/2001GL013014/pdf In this report, they ask the question of what produces what? Does plasma flow produce an electric field? or Does an...

Can someone explain why after a certain voltage, current flows. We were taught that in pn junction when a reverse voltage is applied the depletion region grows wider. Using this no matter what the voltage current should not increase. So why does a current flow when a reverse current is applied.

Homework Statement Hello everyone, I am having a problem whether or not a turbulence at a specific location (let's say A) is isotropic or not. I have calculated the two root mean square values of velocity fluctuations measured at the point A in a fully developed turbulent pipe flow. the first...

Hello everybody, I have a computer case project and I need to create a fanless (passive) cooling. I feel excited of the idea to use paltier thermoelectric coolers, but their efficiency is considered very low, because the hot side is usually exhausted via passive radiators. So I came up with...

I'm looking at an ungounded 3-phase system here for starters. In a perfectly ungrounded system, grabbing a phase seems safe in theory, but in practice (because perfect ungrounded doesn't exist), this is a bad idea. I'm trying to determine exactly WHY. If I have a perfect ungrounded system...

I am currently designing a lubrication system which uses a positive displacement gear pump. So how can I get the flow rate of a lubrication system? i don't know which equation to use. thank you so much.

Sodium ion flows a through a cylindrical ion channel --> diameter = 0.85 um and is 5 um long. potential difference b/w the ends of the channel is 225 mV drift velocity = 0.015 m/s in a period of 1 ms, a total of 15*10^6 ions exit the channel a. total charge exiting the channel in 1 ms =? b...

Hello everyone, i am currently dimensioning a compression system using a vehicle turbocharger and need to find a way to relate the pressure ratio of the compressor and the mass flow rate. (flows trough compressor and turbine are of course separated) For the turbine, one can use Stodola's...

QUESTION: In general: when a flow is considered steady does that mean all properties of the flow are steady? Or: can a flow have steady and unsteady properties?

You have a capillary with a stream of water vapor flowing through. Inside the capillary argon gas is also flowing (in the same direction) with a flow rate of 3 L/min. How high of a flow rate can the water vapor have before it starts condensing on the walls? Flow is laminar and the system is at...

I am looking for some advice on the experiment described below. I am attempting to use electric potential to move negatively charged RNA toward a positive electrode. The procedure is similar to traditional electrophoresis except there is no gel or dies. I attempt to describe the setup below...

Hello, I have to calculate the air flow through a small rectangular opening with following data: - temperature at one side: 1200°C - temperature at other side: 20°C - pressure at hotter side is 3 mm WC lower than the colder side - the length of the opening is 240 mm - the width of the opening is...

In short circuit it is said that there is no resistance. So the current produce heat and wire is burnt. But as the rise in temperature increase the resistance then in short circuit heat must rise the resistance. How can we say there is no resistance in short circuit?

Homework Statement Homework Equations [/B] When a diode is reverse biased positive donor ions are left in the N semiconductor and negative acceptor ions in the P type. And since the N is conected to + and its donnor ions has a large +charge, why no electrons from P cannot cross the junction and...

Homework Statement I have been given a question which I can't seem to get my head around fully for one reason. I keep finding myself stuck with 2 unknown variables. Here is the information given.. V (terminal velocity) = Unknown g (gravity acc.) = 9.81m/s2 d (diameter of particle) = ? Pp =...

So I'm trying to make a Hot-Water Rocket. But I want to make the necessary thermodynamics calculations first. What kind of flow will it be in such systems I think it's obviously going to be an unsteady flow but is it uniform or not? I also would love if you guys linked me to unsteady...

Hey! I am currently working on modeling and solving a scenario with oil and water flow. The flow is supposed to be driven purely by the capillary pressure(Dont mind this too much). The flow in the two phases are given by: q_o = -\frac{k_o(\Delta P)}{\mu_o}\frac{\partial P_o}{\partial x} q_w =...

An ideal Carnot engine is composed of two reservoirs and a working fluid. The hot Reservoir and the cold one have temperatures ##T_1## and ##T_2## respectively, with ##T_1>T_2##. The working fluid is in a phase transition and has temperature ##T_1## at the start of the Carnot cycle. It undergoes...

I've always been taught that in a piping system (only water), if the flow rate doubles, then pressure loss quadruples. But when using the Darcy-Weisbach equation I often find that it is closer to triple. Playing around with viscosity and temperature I've never been able to bring the ratio higher...