What is Transient: Definition and 200 Discussions

ECHELON, originally a secret government code name, is a surveillance program (signals intelligence/SIGINT collection and analysis network) operated by the United States with the aid of four other signatory states to the UKUSA Security Agreement: Australia, Canada, New Zealand, and the United Kingdom, also known as the Five Eyes.Created in the late 1960s to monitor the military and diplomatic communications of the Soviet Union and its Eastern Bloc allies during the Cold War, the ECHELON project became formally established in 1971.By the end of the 20th century, the system referred to as "ECHELON" had evolved beyond its military and diplomatic origins into "a global system for the interception of private and commercial communications" (mass surveillance and industrial espionage).

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  1. Imya

    I Transition of spherically symmetric gravitation

    Outside a static spherically symmetric body in vacuum lies the Schwarzschild metric. However, when observing a contractive sphere from a point near the sphere, it no longer appears spherical. Its opposite end appears stretched for an observer stationary relative to the center of the sphere. In...
  2. user366312

    A What is a "transient" value in the Ising model?

    What is a "transient" value, result, or state in the Ising model? How do we treat these values during the simulation? Do we discard these values? If so, why?
  3. Astronuc

    I Four neutrons form a transient isolated entity - a tetraneutron?

    I was reading another article when this headline from June 22 caught my attention. Collisions hint that four neutrons form a transient isolated entity https://www.nature.com/articles/d41586-022-01634-x An experiment firing helium-8 nuclei at a proton target has generated evidence that four...
  4. C

    Are the states (or set of states) absorbing, transient or recurrent?

    Summary: Determine the absorbing states & communication classes of the given matrix. Hello everyone, If we have a state space of S = {1,2,3,4} and the following matrix: \begin{bmatrix} 0 & 1 & 0 & 0\\ 0 & 0 & 1/3 & 2/3\\ 1 & 0 & 0 & 0\\ 0 & 1/2 & 1/2 & 0\\ \end{bmatrix} Now, given the...
  5. DennisN

    I Discovery: A radio transient with unusually slow periodic emission

    Paper: N. Hurley-Walker, X. Zhang et.al, A radio transient with unusually slow periodic emission (Nature, 26 January 2022) Abstract: The high-frequency radio sky is bursting with synchrotron transients from massive stellar explosions and accretion events, but the low-frequency radio sky has...
  6. okara61

    A Coil excitation adjustment on 3D Ansys Maxwell transient analysis

    Hi. I am making a 3D Ansys Maxwell project to design DC electromagnet. My model as in attached pictures. I have couple of questions. 1- How important the width value of sheet of coil terminal? Altough I did not change number of conductors and current of coil, changing the width of sheet of the...
  7. piyushverma

    Ansys Maxwell: Transient generator simulation torque fluctuation

    I am working on an axial flux generator design, I consisits of 2 rotors and one stator, there are 6 pole pairs and 9 coils. Here is my simulation setup The three phase windings are connected in star configuration through Maxwell circuit. I created two bands enclosing each rotor and then united...
  8. D

    Engineering Question - Calculating Coefficients for 2nd Order Transient Analysis

    Hello everyone, I am struggling with calculating the coefficients for second order transient analysis. For example, when analyzing a underdamped circuit, we know that the equation for voltage or current is xt=e-αt(K1cos(sqrt(ω2-α2)t ) + K2sin(sqrt(ω2-α2)t)). Then in order to determine for...
  9. T

    Calculating Transient Heat Transfer in Pipes with Thick Walls

    Hi Everyone, I am looking to find how much heat can be stored in a concrete pipe of roughly 0.3-0.4m diameter, and an internal diameter of 0.05m. Air will travel through the internal diameter at 500°C and 17.5bar which will provide the heat for the pipes. This system will then be reversed so...
  10. jim mcnamara

    Computer languages tend to be transient

    I want to make a point about computer languages. Sometimes it is more effective to show some examples, then present the concept. This is a list of BASIC (computer language)-- take a peek it goes on forever... See: https://en.wikipedia.org/wiki/List_of_BASIC_dialects Way too many. Most of...
  11. cnh1995

    Engineering Why Does Doubling the Time Solve the AC Transient Equation in an RC Circuit?

    Here, at voltage source zero crossing, cos(2to + pi/4) =0. So, 2to+pi/4 = pi/2 This gives to=pi/8 = 0.3926s. But the given answer is twice the answer I got i.e. 0.7852s. Have I missed anything here?
  12. M

    Engineering Transient circuit analysis problem with a dependent source

    Hi all, I tried to solve this, but I can't find the R(equal). I use the following method. The circuit: For t<0 the switch is closed so the iL(0-)=4 A For t>0 it opens and the iL(∞)=0 A Now, I want to find the value τ=L/R(equal) Then I will use the: iL(t) = iL(∞) + ( iL(0-) - iL(∞) )* (...
  13. V

    Transient vibration of an engine

    How is the transient vibration of a piston engine usually simulated? I know that in order to define the vibration loading you need the mass properties and dimensions of the moving components plus the cylinder pressure curve. And of course you need to know the firing order, V-angle (if...
  14. M

    Sketching Waveforms to represent Transient Responses

    i am completely unsure on what is being asked by this question. i know the word sketch suggests a rough drawing and google shows up roughly what the waveforms should look like but what's thrown me off is the fact that the equation 'b' has twice the frequency as the other two. this is a topic...
  15. user366312

    What is Static, Dynamic, Transient, and Persistent Local Resource in the discussion of Object Server and Middleware?

    What I understand is, I have written something like this myself. What is a Static Proxy and a Dynamic Proxy then? Also, What is a Transient Proxy and a Persistent Proxy?
  16. Garth

    A new kind of radio transient: ERBs, by Ali Frolop et al.

    A new kind of radio transient: ERBs arXiv:1903.12412v1 [astro-ph.HE] 29 Mar 201 Another fascinating paper by Ali Frolop et al. in yesterdays arXiv: Garth :oldwink:
  17. O

    Troubleshooting Motor Simulation Results in Maxwell: Any Suggestions?

    Hello, I'm trying to simulate a 3 phase hysteresis motor with 4 poles, 36 slots, 220 input voltage peak for each phase, 50Hz, specified dimensions and 0.6 N.m output torque in maxwell transient. The magnetic material used is LNG52 which is also known as alnico600, alnico5DG(ACA52) and alcomax...
  18. cnh1995

    Transient in a coupled circuit

    Homework Statement Homework Equations Kirchhoff's lawsThe Attempt at a Solution Applying KVL on primary, di1/dt+i1=5+2di2/dt...1) Similarly for secondary, 2di1/dt= 4di2/dt + i2...2) After solving these equations using Laplace Transform, I got I1= 5-e-0.2t A and I2 = 2e-0.2t-2e-0.25t. I...
  19. J

    Unsteady flow of water being discharged from a tank

    I am currently modeling the altitude that a water rocket can attain. In order to do this i am first modeling the the thrust phase. Due to the water mass decreasing with time (the same goes for the pressure - it decreases over time as the water is expelled out of the nozzle). This is an...
  20. S

    Transient Capacitance Analysis: DC Source, Resistor & Capacitor

    When analyzing the transient development of a circuit containing a DC voltage source, capacitor and resistor in parallel, how might one explain the fact that 1. the voltage drop across the resistor changes with that of the capacitor. 2. The first loop containing the capacitor and DC source seem...
  21. C

    Sketch the waveform to represent the transient response

    Homework Statement Sketch, on a set of common axes, waveforms to represent the transient response of circuits having transfer functions with the following parameters: a) ζ = 0.5, ω = 1×10^3 rad s^-1 b) ζ = 0.2, ω = 2×10^3 rad s^-1 c) ζ = 2, ω = 1×10^3 rad s^-1 Homework Equations wd=wo√(1-ζ^2)...
  22. H

    Find the transient current in this circuit

    Homework Statement Homework EquationsThe Attempt at a Solution I often do circuit. But still there is always stuff i don't get.. I was asked to find 1) I1 I2 I3 immidiately after S closed 2) I1 I2 I3 after sufficient of time 3) I1 I2 I3 immidiately after S opened Just give me clue please...
  23. J

    Transient Response of Electrical Network

    Homework Statement Homework Equations In Capacitance current leads voltage In Inductance current lags voltage For oscillations R = 0 3. The Attempt at a Solution Since current is leading voltage in above question, impedance is capacitive. Book answer is D for both. How? And for 3rd...
  24. J

    Engineering Transient RC Circuit (got answer in s but not in t-domain)

    Homework Statement Homework Equations Vc = ( Initial Voltage - Final Voltage ) e(-RC/t) + Final Voltage 3. The Attempt at a Solution I got the answer through Laplace but am not getting through time domain analysis. Given q across C is 2.5mC C = 50micro F q = CV So V = 50V Initial voltage =...
  25. B

    Transient heat transfer in a cylinder with internal heating

    hi, I met a problem about heat transfer in cylinder, if you can help, I will appreciate it. The question is simple. I want to know the transient heat distribution in a cylinder with internal heating(constant temperature not constant flux). The boundary conditions comprises two constant...
  26. Khang Vu

    Ansys Maxwell Magnetic Transient Help

    I am trying to simulate a linear eddy current brake. To do this, I am modeling my brake as a single magnet moving above an aluminum plate. I plan to measure the drag force on this magnet and calculate my braking force as a superposition of single magnets. Here's my current setup: Model: A...
  27. A

    Ansys Fluent transient pipe flow

    Hello, I am doing a relatively simple problem, but i can't initialise it. I have hot water at 400K moving inside a copper pipe at 300K. I would like to see the time it takes for the copper pipe's temperature to increase to 400. However I can't seem to initialise the temperature of the pipe...
  28. E

    Synchronous generator reactance (Sub, transient, SS)

    Hi I know that when studying fault conditions for synchronous machines you have three reactances: Sub, transient and steady state reactance. Where the magnitude of the reactances are (from smallest to largest) in the same order as previously listed. However, I have tried searching - hoping to...
  29. H

    Transient Energy Balance for Heating a Tank of Water

    Homework Statement In an industrial process, a tank containing 200 liters of water must be heated from a temperature of 293 K to 372 K at a constant pressure. There is a negligible change in the volume of the water. The water is stirred during this process to maintain a uniformly distributed...
  30. R

    Ansys Maxwell- Transient torque fluctuating problem

    Hii Friends, I was trying to model an Induction motor 5 KW in ANSYS Maxwell. The final output of Transient torque looks like shown below. It fluctuates with average torque almost equal to zero Nm. The input passed is a sine wave current with 120 deg phase shift. Any Suggestion will be highly...
  31. Biker

    Heat transfer: transient state

    Hello, I have studied about heat transfer through conduction only in steady state but I wondered about this problem that I created. Suppose you have a box that is insulated from all sides but Suppose a constant heat flow from that wall. Inside that box you have M kg of water at the same...
  32. A

    I Difference between transient and steady state solution

    In driven SHM, we ignore an entire section of the solution to the differential equation claiming that it disappears once the system reaches a steady state. Can someone elaborate on this?
  33. A

    Transient Heat transfer from water through pipe to ground

    Hi I am trying to do a transient heat transfer calculation. The water flowing through the pipe is laminar (1 m/s, id = 0.0127 m, Re_d = 0.01) transferring heat to the pipe via convection, then the pipe (od = 0.015875 m, l = 144 m) transfers heat to the ground again via conduction. I found this...
  34. Abdullah Kacar

    APDL - Transient Structural - Exporting stresses over time

    I'm writing my master thesis and need to export forces over time in Transient analysis. I tried using the force reaction but it shows the result as zero. BTW I'm not trying to get the forces from the nodes which is supported, with these i get results. But with the nodes with no support i get...
  35. S

    Ansys workbench transient analysis

    Hello i have a cyclinder that i want to apply pressure to. The pressure starts from a higher value and then drops as time progresses. Can someone tell me how to apply pressure based on time in ansys workbench?
  36. D

    Electronics - Have I found the transient current correctly?

    Homework Statement A step voltage of 120v is applied to a series CR circuit. C = (4x10^(-6))F R = (20x10^(3))Ω When the capacitor is fully charged the supply voltage is removed. Using KVL and Laplace transforms obtain an equation for the transient circuit current, given when t = 0, the voltage...
  37. D

    Engineering Laplace tranforms, transient current series CR circuit

    Homework Statement A step voltage of 120v is applied to a series CR circuit. R = 20KΩ, C = 4µF 1. Deduce, using Kirchoff's voltage law and Laplace Transforms, an expression for the transient circuit current. 2. Using the equation obtained in 1. deduce the equations for the transient voltages...
  38. 1

    A Deformation in static and transient case

    Hi all, I have a doubt that I would like to solve with oyu help. Basically I want to calculate forces on a solenoid due to the magnetic field it produces and than calculate deformation. I consider 2 cases: 1/ Static I did analytic calculation for force calculation, and i made FEM simulation...
  39. Z

    Heat flux analysis with transient heat conduction

    Homework Statement I have one dimensional heating system. In the center is heating source which is heating two PVC elements located on both sides of the heating source. Heat distribution in other dimensions is negligible because of insulation. Thickness of one PVC element is 0,051 m and surface...
  40. gmm

    Transient Response RLC: Calculating Vc(t) for a Series Circuit | 9121 Problem

    9121. Problem If we assume that the initial voltage, Vs, is equal to zero, and it rises to five volts at t = 0, derive an expression for the voltage across the capacitor as a function of time. That is, calculate Vc(t) 2. Homework Equations this is a series RLC so I'm trying to calculate...
  41. E

    250VDC Line, Transient detection

    Any of you guys know of any instrument to record both the DC and at the same time the AC transient of a DC line. Thanks.
  42. T

    Droop control (load sharing in AC Mains distribution networks)

    Hi, I have quite a superficial understanding of Droop control: http://www.openelectrical.org/wiki/index.php?title=Droop_Control https://en.wikipedia.org/wiki/Droop_speed_control I'm not after a super technically detailed explanation, but if anyone has any more detailed sources for how it is...
  43. cehen

    ANSYS transient thermal boundary conditions

    Hi all. I don't have as much experience with thermal analyses in ANSYS, and I can't quite figure out a problem that I'm working on. I'm trying to find the temperature distribution in a box that has a circle in the center. I want to define constant temperature b.c.'s at the walls and the circle...
  44. ESMAT 1995

    Lumped system analysis in transient heat conduction

    Homework Statement so, i had this question where i had a sphere and a cylinder with given dimensions and propreties ( roh, C and k) he also gave me initial temperatures, then both of them dipped in a bath of water of given temperature but unknown h ( convective coefficient) then he gave me the...
  45. C

    Peak-hold equivalent amplitude for transient vibration

    I have a question regarding transient vibration data I received that was processed into a peak-hold equivalent amplitude (units = g). I have come across peak-hold before which is a type of "averaging" that retains the highest values from each estimate in random vibration overlap processing and...
  46. M

    A Is Transient Flow Caused by Changes in Velocity's Direction in Pipelines?

    Hi every one; Transient [Fluid Transient in Pipelines] is result of changing in momentum and momentum is result of changing in velocity. Velocity is a vector parameter. It means that Velocity's change is due to changing in velocity's quantity or velocity's direction. All discussions about...
  47. R

    Transient heat transfer in a sphere

    Homework Statement A metal sphere is subjected to a heat flux, 5000 W/m2. It is originally at 20 C. How long does it take to heat to 90 C? D = 5 cm density = 8522 kg/m3 cp = 0.385 kJ/kg-K k = 104 W/m-k Homework Equations rate of heat input = rate of heat accumulation -k*A*dT/dr = m*cp*dT/dt...
  48. I

    I Transient Absorbtion Spectroscopy

    Hello there! The picture attached in file shows typical spectrum of transient absorption spectroscopy. Is it possible to have the same components in quantum dots?
  49. happytolearn

    Transient thermal analysis in ANSYS

    I want to do a transient thermal analysis in butt welded joint.The heat flow I have given 3200 watt(Q = efficiency x current x voltage = 0.8 x 160 amp x 25 volt)to the welding zone, given 20 load step(as welding is completed in 20 sec),convection co-efficient = 11.14, emissivity = .4 and applied...
  50. M

    Problems in excitation and boundary while doing ANSYS transient

    hi, I m designing a current transformer in ansys. initially i designed a 3D toroidal (split) core. i wanted to get the B-H curves by varying different permabilities of core with different frequencies.the current injection is through the conductor which is in centre of core. but i am facing a...