Unanswered Questions
2,252 questions with no upvoted or accepted answers
18
votes
1answer
387 views
Is there a method to determine the runoff for arid areas in developing countries?
Note: this question was totally rephrased and expanded on, addressing the comments and questions posed to the first version.
The de-facto standard source for runoff calculations in South Africa is ...
13
votes
1answer
337 views
Determining RTK parameters for runoff analysis
I am examining a watershed and determining runoff using the RTK method. I basically use a 'guess and check the hydrograph' method right now. I've seen calibrators that use a mutation and convergence ...
11
votes
1answer
171 views
How do the bubble oscillations in two-phase flows affect the dissipation rate of turbulent kinetic energy?
I am investigating the effects of bubble oscillations (calculated using the Rayleigh-Plesset equation for bubble dynamics) on the turbulence in two-phase flows. Since I am using cryogenic fluids, the ...
9
votes
0answers
1k views
ANSYS APDL Shape memory effect option of SMA not working
I am trying to define the material properties of a shape memory alloy material in ANSYS APDL V15. There are material properties for Superelastic materials (SUPE option) and material properties for ...
8
votes
0answers
196 views
Forcing a part into “home position”
I have a design with two parts (at the moment):
a fixed 10cm ring with vertical tracks
a freely rotating block with a cut that may freely slide along that tracks:
I'm trying to find a low profile ...
8
votes
0answers
162 views
Sketching an engineering system in healthcare
I am about to do a project about engineering systems in a Systems Engineering course.
I need to sketch an engineering system in which clinical decision support systems are being used to diagnose ...
8
votes
1answer
125 views
How can I estimate blocking window distance in an sCMOS sensor setup?
I am trying to establish an appropriate distance between a spectrograph output window and a CMOS sensor.
The spectrograph creates a focused image on the CMOS sensor but I am trying to restrict the ...
7
votes
1answer
154 views
How to optimise feed-forward control of a process based on a prediction using the prediction confidence?
I'm looking for a control method for a production process with the following characteristics:
1 control variable
many process parameters (+-50)
1 resulting variable
continuous measurement of ...
7
votes
0answers
495 views
Incompressible 2D pressure-driven flow: for Navier-Stokes equations in nondimensional form, how should I express pressure boundary conditions?
*I have updated this question.
I'm using two codes for modeling incompressible, two-dimensional flow out of a tank. My fluid dynamics experience is pretty basic; I'm using the codes to understand a ...
7
votes
0answers
485 views
BER peroformance of MPSK and MQAM in Rayleigh fading channel
I have a question regarding bit error rate (BER) performance over the Rayleigh channel. I observed BER performance over the AWGN channel using Simulink in MATLAB. I used to change the "SNR" parameter ...
7
votes
0answers
6k views
Residuals of continuity not converging
I'm simulating a turbine.
The convergence of solution is monitored by checking the residuals of the numerically solved governing equations.
The "viscous-spalarat-almaras" model is used, and used air ...
6
votes
2answers
197 views
Calculation of the stored energy for a heat storage tank
There is a heat storage tank that is directly loaded from the top and the heat is also taken from the top.
The colder water from the heating circuit return flow enters the heat storage tank at the ...
6
votes
1answer
88 views
LED Lumen Calculations
I am using an LED as a point source for a school project. I have two questions in regards to the LED(s).
I know that light follows the inverse square law when measuring perceived brightness, but all ...
6
votes
1answer
190 views
System Dynamics Modeling
I am trying to model this system but am having difficulties in setting up the equations of motion. This is a simplified model of a motorcycle suspension system, where P is the ground in the image ...
6
votes
1answer
305 views
Industry standard factor of safety for ballast design
What design standards exist for the design of ballast against uplift forces, and what factor of safety against uplift do these design standards promulgate? I am familiar with a typical FS of roughly 1....
