Talk:Analogical models

message: Note: The discussion below was originally on the Impedance matching Talk article, however it was moved here because this seems a more appropriate topic for Analogical models. Sholto Maud 02:34, 5 May 2006 (UTC)

message: 1. emf analogous to torque = fR 
2. current analogous to angular velocity = dθ/dt
::*2.1 is angular velocity also = to ɯ*t = 2* \pi*f = 360*f ?
3. rotational resistance analogous to electrical resistance = rR =fR/(dθ/dt)
3. Power = Voltage*Current = Current*Current*Resistance = angular velocity*dθ/dt*fR/(dθ/dt)
4. Power = torque*angular velocity
hence
5.  torque*angular velocity = dθ/dt*dθ/dt*fR/(dθ/dt)
And so torque = angular velocity*fR/(dθ/dt) = emf
Here is a table that gives maximum power in resistance matching. It might be beneficial to construct the analagous table using rotational power. 
Effect of Connecting Various Load Resistances to a Practical EMF Generator
Load Resistance (Ohms)	Internal Resistance (Ohms)	Total Resistance (Ohms) RT	Current (amps) I	Load Voltage (Volts) VL	Load Power (Watts) PL	Internal Power (Watts) Pint	Total Power (Watts) PT	Power Efficiency %
RL(oad)               	Rint(ernal)               	RT(otal)= RL + Rint       	= E/RT          	= I(RL)                	= I^2(RL)            	= I^2(Rint)                	= PL+Pint             	= PL/PT
0                     	6                         	6                         	20              	0                      	0                    	2400                       	2400                  	0 %
2                     	6                         	8                         	15              	30                     	450                  	1350                       	1800                  	25%
3                     	6                         	9                         	13.3            	40                     	533                  	1067                       	1600                  	33.3%
6                     	6                         	12                        	10              	60                     	600                  	600                        	1200                  	50%
12                    	6                         	18                        	6.7             	80                     	533                  	267                        	800                   	66.7%
18                    	6                         	24                        	5               	90                     	450                  	150                        	600                   	75%
infinite              	6                         	infinite                  	0               	120                    	0                    	0                          	0                     	100%
Analagous table in rotational systems (needs experiemental data and definition of load rotational resistance)
Load Rotational Resistance	Internal Rotational Resistance	Total Resistance 	angular velocity = dθ/dt	Load torque = fRL	Load Rotational Power PRL	Internal Rotational Power PRint	Total Rotational Power PRT	Rotational Power Efficiency %
rRL                       	rRint                         	rRT = rRL + rRint	= fR/rRT                	= fR/rRT* rRL    	= (dθ/dt)^2 * rRL        	= (dθ/dt)^2 * rRint            	= PRL+PRint               	= PRL/PRT
0                         	6                             	6                	20                      	0                	0                        	2400                           	2400                      	0 %
2                         	6                             	8                	15                      	30               	450                      	1350                           	1800                      	25%
3                         	6                             	9                	13.3                    	40               	533                      	1067                           	1600                      	33.3%
6                         	6                             	12               	10                      	60               	600                      	600                            	1200                      	50%
12                        	6                             	18               	6.7                     	80               	533                      	267                            	800                       	66.7%
18                        	6                             	24               	5                       	90               	450                      	150                            	600                       	75%
infinite                  	6                             	infinite         	0                       	120              	0                        	0                              	0                         	100%
Sholto Maud 11:07, 4 May 2006 (UTC)
thread_title: Pseudo summary

message: Many physical processes are described by a second-order linear differential equation:
:F=m\frac{d^2x}{dt^2}+r\frac{dx}{dt}+gx
where F is a generalized force, m is a generalized mass, r is a generalized friction coefficient, and g is a generalized potential.
     	Mechanical rectilineal	Mechanical Rotational	Electrical   	Acoustical	
x    	Linear distance       	Angular distance     	Charge       	          	
dx/dt	Linear velocity       	Angular velocity     	Current      	          	
F    	Force                 	Torque               	Voltage      	          	
r    	Friction              	Friction             	Resistance   	          	
m    	Mass                  	Moment of inertia    	Inductance   	          	
g    	                      	                     	1/Capacitance	          	
Energy is the general force times the general distance, while power is the general force times the general velocity.
* Also added this table to the Analogical models page, making it even more scrappy. But youse can work out what is best...must go. Sholto Maud 04:13, 4 May 2006 (UTC)
thread_title:  Dynamical analogies table 

message: Perhaps a good issue for the article:
* Structural analog: same "network structure" and of Lumped elements. (if the internal parameters are not ajusted, they may be not functional analog).
* Functional analog: same black box, that is, same input/output behaviour. (example Thévenin equivalent circuits).
They are different things, but both define formal "analog".
--Krauss (talk) 12:11, 18 December 2014 (UTC)
thread_title:  Structural vs functional analogs: two formal analog definitions 

message: Hello fellow Wikipedians,
I have just modified  on Analogical models. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20070626024800/http://www.as.wvu.edu:80/coll03/phys/www/OJ/Heavisid.htm to http://www.as.wvu.edu/coll03/phys/www/OJ/Heavisid.htm
When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at ).
Cheers.—InternetArchiveBot (Report bug) 08:43, 12 October 2016 (UTC)
thread_title:  External links modified 

message: The use of current/voltage compared to motion/force is inconsistent. The consistent model for inertia is inductance and the analog of a spring is a capacitor. Then modeling electrical current as motion & force with voltage is consistent. Michael McGinnis (talk) 04:16, 25 March 2019 (UTC)
replies: text: It's a perfectly valid model called the mobility analogy  It is widely used and has certain advantages.  There are many possible models, there is no one correct analogy.  The choice depends on the parameters of the problem one is trying to address. SpinningSpark 13:28, 25 March 2019 (UTC)
thread_title:  The first figure is inconsistent 

message: The text of the Hydraulic Analogy does not match the current linked page, which is about electrical-hydraulic analogy only. In any case, it is not clear that there is an analogy between hydraulics and maths: the hydraulics obeys the maths: what it is describing is a computer not a simulator, I guess. (Yes I know there are analog computers, but still.) Rick Jelliffe (talk) 04:17, 18 June 2023 (UTC)
thread_title:  Hydraulic Analogy strange