Unanswered Questions
1,630 questions with no upvoted or accepted answers
18
votes
1answer
280 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 ...
11
votes
1answer
126 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 ...
11
votes
0answers
238 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 ...
10
votes
4answers
773 views
Preventing condensate backup at startup with orifice (venturi) steam traps on medium pressure batch process mains?
I am working with 1" medium pressure steam mains (45 psig) for a batch process. Time between batches is usually short (to the order of minutes) but depending on the day the delay can be hours, and ...
9
votes
0answers
104 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 ...
9
votes
1answer
265 views
Response of a system to a step function (Heaviside function)
I'd like to compute the response to a step function of a electrical/thermal system. Generally I can "easily" compute the transfer function $H$:
$$H(\omega) = \frac{V_{out}(\omega)}{V_{in}(\omega)}$$
...
9
votes
1answer
395 views
Differences between 2D hydrological modelling programs eg. HECRAS 5.0 (2D), TUFLOW, MIKE Flood
Just wondering what the difference is between 2D flood modelling programs. I am primarily considering whether HECRAS 5.0 (2D - currently in Beta) would be an acceptable alternative for simple 2D flood ...
9
votes
1answer
196 views
How to design the most hydro/aerodynamic shape for a 'vehicle' that goes back and forth (using ANSYS)?
I am interested in making a very small scraper blade that moves back and forth along a submerged surface, however I need to make it as hydrodynamic as possible so I disturb the liquid as little as ...
8
votes
1answer
759 views
Principle of Virtual Work vs Castigliano's (Second) Theorem
I had a look online and into some literature however I did not seem to find a good comparison for the two different methods. They are both used for determining displacements and slopes (rotation by ...
8
votes
1answer
94 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 ...
8
votes
1answer
463 views
Tolerance for Beam With Cope End
I need to have some beams fabricated with copes on the ends. They will be set on top of existing steel trusses, and used to replace undersized purlins to shore up existing rafters (hence the need ...
7
votes
1answer
121 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
426 views
How does LTE eNodeB set the Base Station output power?
I'm interested into the power radiated out of an eNodeB (LTE/4G) radio base station: which parameters does this power depend on, if they are constant or relying on the environment...
All of this in ...
7
votes
0answers
138 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 ...
7
votes
0answers
4k 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 ...
