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• Efficiency Slope Comparison
• Determining Torque
• Torque, Horsepower, Efficiency
• Converting Bar to PSI
• Viscosity
• Gas Laws
• Velocity of Escaping Compressed Air
• Absolute Pressure of Steam
• Standard Units of Measurement

Tesla's formula for determining torque (from patent):

"Owing to a number of causes affecting the performance, it is difficult to frame a precise rule which would be generally applicable, but it may be stated that within certain limits, and other conditions being the same, the torque is directly proportionate to the square of the velocity of the fluid relatively to the runner and to the effective area of the disks and, inversely, to the distance separating them. The machine will, generally, perform its maximum work when the effective speed of the runner is one-half of that of the fluid; but to attain the highest economy, the relative speed or slip, for any given performance should be as small as possible. This condition may be to any desired degree approximated by increasing the active area of and reducing the space between the disks."

First of all Tesla was describing a dynamic relationship between his disk turbine – he was not describing an exact mathematical equation. In order to develop an equation that will work across fluids, you must deal with the mass and viscosity of the fluid.

Several equations to start with are:

a) momentum = mass x velocity

b) kinetic energy = (mass x velocity (squared))/2

c) power = torque * angular velocity

Engineers have also developed a working relationship between torque and fluid viscosity in the following equation:

Torque = (3uVr^2)/2h

where:
V = velocity of the fluid in (meters/sec)2pi

u = the viscosity of the fluid (air = .0000179)

r = radius of the disk (in meters)

h = half of the distance between the disks (in meters)

Therefore: Torque (Nm) = (3(.0000179) x 628 x 1*2)/2 x 0.125 x .001 and Torque = 134.9 Nm for the other side of a 1 meter radius disk

- Ken Rieli

Bar to Psi Chart

Bar	Psi	Â	Bar	Psi	Â	Bar	Psi	Â	Bar	Psi
1	14.5037738	Â	26	377.0981188	Â	51	739.6924638	Â	76	1102.286809
2	29.0075476	Â	27	391.6018926	Â	52	754.1962376	Â	77	1116.790583
3	43.5113214	Â	28	406.1056664	Â	53	768.7000114	Â	78	1131.294356
4	58.0150952	Â	29	420.6094402	Â	54	783.2037852	Â	79	1145.79813
5	72.518869	Â	30	435.113214	Â	55	797.707559	Â	80	1160.301904
6	87.0226428	Â	31	449.6169878	Â	56	812.2113328	Â	81	1174.805678
7	101.5264166	Â	32	464.1207616	Â	57	826.7151066	Â	82	1189.309452
8	116.0301904	Â	33	478.6245354	Â	58	841.2188804	Â	83	1203.813225
9	130.5339642	Â	34	493.1283092	Â	59	855.7226542	Â	84	1218.316999
10	145.037738	Â	35	507.632083	Â	60	870.226428	Â	85	1232.820773
11	159.5415118	Â	36	522.1358568	Â	61	884.7302018	Â	86	1247.324547
12	174.0452856	Â	37	536.6396306	Â	62	899.2339756	Â	87	1261.828321
13	188.5490594	Â	38	551.1434044	Â	63	913.7377494	Â	88	1276.332094
14	203.0528332	Â	39	565.6471782	Â	64	928.2415232	Â	89	1290.835868
15	217.556607	Â	40	580.150952	Â	65	942.745297	Â	90	1305.339642
16	232.0603808	Â	41	594.6547258	Â	66	957.2490708	Â	100	1450.37738
17	246.5641546	Â	42	609.1584996	Â	67	971.7528446	Â	125	1812.971725
18	261.0679284	Â	43	623.6622734	Â	68	986.2566184	Â	150	2175.56607
19	275.5717022	Â	44	638.1660472	Â	69	1000.760392	Â	175	2538.160415
20	290.075476	Â	45	652.669821	Â	70	1015.264166	Â	200	2900.75476
21	304.5792498	Â	46	667.1735948	Â	71	1029.76794	Â	250	3625.94345
22	319.0830236	Â	47	681.6773686	Â	72	1044.271714	Â	300	4351.13214
23	333.5867974	Â	48	696.1811424	Â	73	1058.775487	Â	500	7251.8869
24	348.0905712	Â	49	710.6849162	Â	74	1073.279261	Â	750	10877.83035
25	362.594345	Â	50	725.18869	Â	75	1087.783035	Â	1000	14503.7738

• Bar is the atmospheric pressure at the sea level, which equals to 100 kilopascals.

• Psi is 1 pound of force per square inch.

• 1 Bar = 14.5037738 Psi (Pound Per Square Inch)

MORE TO COME