Flow Definition and 1000 Threads

  1. danielng245

    Please help calculate flowrate frm blower to push water down

    How to calculate how much flowrate from blower i can push water pool 2,75m*1,8m down by 1,25m in 1 sec? Note : Blower Pressure 0.03 bar - 0.035 bar There is an empty room above the water pool with dimension of 2.75m*1.8m*1.7m This process happen in a closed chamber...
  2. BeautifulLight

    Can you stop current flow with a resistor? And POTs?

    This thread will concern the workings of potentiometers, but I could use some help tackling something first. I will explain in my next post! Assume I have shorted out a battery with some resistor. I always thought that if you had a high enough resistor value, you could stop current from...
  3. N

    Is current harmful when it doesn't flow out of you?

    So say if you're in a vacuum, breathing via a space suit (so you're not grounded and are surrounded by perfect insulation) and you touch something with very high voltage relative to you, would you completely safe no matter how high the voltage is? Note I've made the setting a vacuum deliberately...
  4. F

    Understanding Diode Current Flow: A to B or No Flow?

    Homework Statement What is the current flow when a diode is connected in series with a resistor and battery.The cathode of the diode indicated as A is connected to the positive battery terminal.The Anode of the diode indicated as B is connected to the one leg of the resistor and the other is...
  5. V

    How to calculate the circulation flow in makeup water

    Actually i have to calculate the make up water capacity of cooling tower . M= E+B+W . but while calculating the particulars , i am needing the circulation flow rate . i searched it in internet also but it simply showing 18000 so getting confused . Is it 18000 a constant or anything there to...
  6. M

    Simulation error messages solidworks - invalid goals

    I am running a simulation on a flat plate heat exchanger and the solver is coming up with some error messages. The first says that a vortex crosses the pressure opening and the second says that my heat transfer rate goals are invalid. How can I get the heat transfer goals to be valid as I need...
  7. S

    Flow Rate, Velocity and Pressure relationship

    Hello everyone, I'm new to this forum and this is my first post so go easy! I have an engineering problem which I am uncertain as to how to solve. I am trying to design a basic ballast system for pumping seawater. The idea is to use compressed air to evacuate the water through a series of...
  8. S

    Pressure Added to a Flow Loop by a Pump?

    Hi there, I have set up a flow loop for a uni experiment that will teach other students about the bernoulli equation. The loop will use a few working section that will increase and decrease pressure due to diameter, velocity and height changes. I first set-up my loop with the pump at the end...
  9. B

    Calculating temperature and heat flow in a wall

    Homework Statement Consider the following multi-layer wall consisting of an interior insulation layer and an external light-weight concrete layer. Calculate the heat flow thorugh the structure and the temperature at the interface between the two materials. Layer 1: Thermal insulation...
  10. R

    Speed of electron flow through a conductor

    Is the speed of electron flow through a conductor such as copper equivalent to 'c'? I've heard of this being implied several times, but is it a fact? I know it can't be exactly the same as 'c' because we are not talking of energy propagating though a vacuum.
  11. J

    What is the difference between blood flow and cardiac output

    according to this one source, cardiac output (vascular) = blood flow (http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/APIINotes5%20cardiac_equations.htm) However, their equations do not match: Cardiac output (CO)= Stroke volume * Heart Rate Blood Flow = cross sec area of vessel times...
  12. S

    Nozzle problem between subsonic and supersonic speed & nozzle area

    Hi all, I have really a confusion between subsonic and supersonic speed evolution when the area decrease or increase I have a problem to understand why in supersonic regime the velocity evolution in a nozzle is adverse of the subsonic regime? for example in subsonic regime, when the area...
  13. M

    Help understanding flow of electricity

    I know very little about electricity, but I'm trying to understand it better. I'm trying to wrap my head around something- I have heard it said that, "the flow of electricity through a circuit is due to the movement of electrons". While this explanation sounds simple enough, I have some...
  14. T

    Thermodynamics flow processes,

    Homework Statement Air at 1 bar and 20°C flows steadily at a rate of 2 m^3/min into a compressor. It leaves at a pressure of 15 bar and 120°C. The heat lost from the compressor is 10% of the work transfer to it. Find these work and heat transfers, assuming that air behaves as a perfect gas and...
  15. J

    Rayleigh Flow and Stagnation Conditions

    Homework Statement \[/B] The question I want to ask is how do you relate conditions such as To* and To,1 and To,2, where To,1 and To,2 are the stagnation conditions at the entrance and exit. This is the problem I was doing. Standard atmospheric air is drawn steadily through an isentropic...
  16. A

    Current flow in infinite sheet, and shape of isocurrents

    I am trying to determine the size of a conductive 2-D sheet that has a specified degree of increased resistance (or reduced conductivity) compared to an infinite sheet. Imagine that electrons enter the infinite sheet and exit the sheet at 2 points which are 1 unit of distance apart and aligned...
  17. Suresh Gadekar

    Choked Flow in 1/4" Pressure Regulator at 3.5bar

    Is it possible to have choked flow in a 1/4" diameter pressure regulator with pressure difference of 3.5bar?
  18. Suresh Gadekar

    Air Flow Rate in 1/4" Pipe at 1 Bar Pressure

    is it possible to have a flow rate of 10lit/sec in a 1/4" diameter pipe at 1 bar pressure ?
  19. P

    Is the mass flow rate in a regenerative vapor power cycle constant?

    Does the mass flow rate differ depending on whether it's after the feedwater heaters or before the turbines or is it just constant throughout the entire system?
  20. Suresh Gadekar

    Can Air Flow 10Lit/Sec in 6.35mm Pipe @ 1Bar?

    Is it possible to have a flow rate of 10lit/sec for air in a pipe of diameter 6.35mm (1/4") at a pressure of 1 bar? As in this case, the velocity of air nearly equals the velocity of sound.
  21. C

    Repairing MKS 1179A Mass Flow Controllers: A Scientist's Journey

    Would love to talk to anyonw that is familiar with MKS instruments 1179A Mass Flow controllers. I have taken apart a MKS mass flow controller and am trying to fix it but I am not sure where to get replacement parts, or even what some of the parts do.Most specifically is a small block on top of...
  22. D

    Is current the flow of protons or just the movement of holes

    I know that current flows in the opposite direction of electrons but I'm confused as to whether it is the movement of holes like in a semiconductor or if there are actual positive particles flowing that way.
  23. Feodalherren

    Computational fluid dynamics: steady 2D flow

    1. Homework Statement Homework Equations CFD The Attempt at a Solution I'm a bit confused by this question. So at first what I do for the problem on the left, I find the changes in the velocities in X and and Y on all four sides. I notice that the values on the diagram to the left are...
  24. U

    Finding volumetric flow rate from pressure?

    Hello everyone, I am quite new to Fluid dynamics, so I would like to ask for your help. Is it possible to calculate volumetric flow rate from the instantaneous pressure? We need to know the flow rate of the air entering the cylinder in the engine due to the suction pressure. It is required to...
  25. B

    Calculating flow of air from explosive decrompression

    Hey! Making a game. Say we have a room of 8*12*3 meters. It has the pressure of 1 atm and suddenly there's a hole of one cubic meter in a wall and outside it's space vacuum. Don't know if it counts how much air is inside the room or if that would be measured in pressure, say we have enough...
  26. Suresh Gadekar

    Does a Pressure Regulator Maintain Equal Flow Rates at Inlet and Outlet?

    Is flow rate at inlet of pressure regulator ( not relief valve) equal to flow rate at outlet ?
  27. N

    Electric charge flow in AC and DC

    Can I say that energy transmitted in DC by electrons flow like ants walking align and in AC by electron vibration like water wave ?
  28. samjohnny

    Flow Through Orifice Homework: Bernoulli's & Motion Eqs

    Homework Statement Please see attached. Homework Equations [/B] v = u + at s = ut + ½ at² v² = u² + 2as The Attempt at a Solution I've managed to get the first part of the question applying Bernoulli's principle and then the equations of motion above by considering separately the...
  29. throneoo

    Laminar Flow : shear force on walls

    Homework Statement a viscous fluid with viscosity η flows through a circular vessel of length L and radius R under a pressure difference of P. Assuming the flow is laminar, calculate: a)the force on the walls of the vessel. b)the net force on the vessel. Homework Equations Hagen-Poiseuille...
  30. P

    Determine the Rate of Change of Pressure Across a Valve

    Hello, I am Primarily a Software Engineer, but have some background knowledge from my A-Level and Uni days. However, I have the following problem. I'd like to find out the rate of change in pressure across a valve. Here are the things I know about the system: Cv at 100% open = 0.004 (I...
  31. C

    Calculating Flow Rate for CO2 Cylinders System

    Hello guys, I need to calculate the flow rate for the following system. 2 lines of CO2 cyclinders at 60 bar. Each line (1/2'') goes to a 1/2'' PSV valve. Downstream the 2 PSV the line are collected together into 1'' pipe. The two PSV are identical and as per datasheet they have the following...
  32. P

    Calculate Flow Rate of Sand in Inclined System

    Hi. First of all, I should mention that I'm quite a novice in both physics and engineering. Let's consider an hourglass (or a silo) that is inclined at a constant angle. I'm unsure of how to calculate the necessary diameter of an orifice for a given mass or volume of granular matter to...
  33. O

    Discover How to Measure Flowrate Through Varying Tube Diameters

    I have a setup where there is a source of air pressure, a tube through which the air flows, a connector through which air flows, and a flow meter which reads the flowrate of the air at the end. The final goal is to use the readings from the flowmeter to determine the diameter of the tube through...
  34. Alex Mercer

    Correct electric charge/current flow & left/right hand rule?

    Hello there, people! I am quite new here; in fact, this is my first post. I am quite strange to this place. Feeling kinda welcome, though. Okay, so short to the point. I am an 8th grader, and my school just started teaching us about electricity. Well, the basics. I knew much about it, much...
  35. It's me

    Callen Thermodynamics 2.8-2 matter flow equilibrium

    Homework Statement A two component gaseous system has a fundamental equation of the form $$S=AU^{1/3} V^{1/3} N^{1/3} + \frac{BN_1N_2}{N}$$ where $$N=N_1+N_2$$ and A and B are positive constants. A closed cylinder of total volume 2V_0 is separated into two equal subvolumes by a rigid diathermal...
  36. J

    Calculations for Poncelet (undershot) waterwheels

    Could anyone provide me with, or point me in the direction of, any calculations for the design of Poncelet water wheels? Number of blades and blade shape/curvature in particular. I've had a trawl through the internet and looked through some papers but can't find much understandable information.
  37. C

    Compressible Flow, Pressure and Mass Flowrate

    I am doing a lab report and it is to do with compressible flow through rotameters. An upstream and downstream rotameter to measure flow rate with a needle valve between the two. The needle valve acts as a fixed orifice in one part of the experiment. Then the inlet pressure is altered. Plotting...
  38. J

    Process flow diagram for production of hydrogen

    In the following process flow diagram for the production of hydrogen, why is the amine column placed after 2 heat exchangers?
  39. G

    Flow rate/pressure in a venturi

    Homework Statement Hi Guys, I have found that as flow rate increases the pressure difference in the sections of the venturi increases. Would someone please mind explaining in words why as I'm not sure. Homework EquationsThe Attempt at a Solution Well I know that when the fluid gets to a...
  40. U

    Quark Scattering and Quark Flow Diagrams

    Homework Statement (a) Find energy of incoming beam that creates highest cross section (b) What are the differences in the two reactions, using quark diagrams? (c) What would the peaks of the two reactions be like? Homework EquationsThe Attempt at a Solution Part(a) [/B] Cross section is...
  41. J

    Engineering Current Flow in a Parallel Circuit

    Hi, I'm taking a basic electricity course right now and I'm having trouble understanding a formula. The way they have their example makes no sense to me. Can anybody verify that their example is correct and explain a little bit for me? See attached file.
  42. Y

    Compressed nitrogen v flow rate question

    Currently i have a system using bulk argon and i am changing to nitrogen. To trial this i am going to use cylinders of OFN(oxygen free nitrogen). how do i caculate how many cylinders i need based on a flow rate of 16 liters/min. Thanks
  43. neomahakala108

    A question on electric current's density & flow.

    is this true? thanks for help. i wished to abstract (generalize on topic) from electric current in physical wires, to for example in air. i hope this is in proper forum section. ---- Electric current's density J depends on electric current's intensity I measured in (A) & on conductor wire's...
  44. arthurchen

    Laminar flow exits an inclined tube

    I am working on a problem in which viscous flow comes out from an inclined tube, forming some kind of a fountain. In the tube the fluid is Newtonian and the flow can be treated as Poiseuille flow. I want to study the movement of the fluid after it leaves the tube. Can someone point me about the...
  45. M

    Air flow over a circular cylinder

    Hi, Could you explain the reason why the velocity varies in the wake region behind the cylinder in "flow over a circular cylinder"? the velocity variation is, minimum at a point parallel to the centre point of the cylinder and increases to free stream velocity as the vertical distance increases...
  46. J

    Aeroengines/Fluid Mechanics - Steady Flow

    Homework Statement See Fig.2.4a, let the gases flowing through the nozzle control volume be perfect with Cp = 1.004kJ/kg.K Determine V9 if T5 = 1000K, T9 = 670K and V5 = 120ms^-1. Homework Equations I've detailed the equations in the attached pdf for clarity. The Attempt at a Solution See...
  47. S

    Water Pressure in an Isolated System

    So I'm more into electricity, so fluids is not really a forte at all. But I have been thinking about this, and there must be some fundamental issue in the way that I view fluid pressure. Conditions: 1. I have a metal pipe, incompressible 2. There is water in the pipe, (incompressible? ...
  48. M

    Volume flow rate and mass flow rate

    Hello there, so I have answered my question from fluid systems but the answer doesn't look right ;/ and I have no idea what have I done wrong. Can you please check and correct where it's wrong ? ;) here is the question: A pipe contains a gradually tapering section in which its diameter decreases...
  49. L

    Mass flow rate for compressible flow

    I am confused about the relation of mass flow rate with different mach numbers in a compressible flow. In wikipedia (http://en.wikipedia.org/wiki/Choked_flow), I read the following: "Although the gas velocity reaches a maximum and becomes choked, the mass flow rate is not choked. The mass flow...
  50. B

    Water vs. water/glycol flow rates

    I'm trying to get a rough idea of how flow rate through a round, sharp edged orifice is affected when a fluid is water/glycol versus pain water. In this circumstance, it's 30% water, 55% Dihydroxydiethyl Glycol and 15% Polyalkylene Glycol. I don't need exact numbers at this point, just a...
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