Factores de conversión

1 Factores de conversi n Dr. Carlos Rubio Maya Facultad de Ingenier a Mec nica, Septiembre 2011. DIMENSION METRICO METRICO/INGLES. Aceleraci n 1 m/s2 = 100 cm/s2 1 m/s2 = f t/s2. 1 f t/s2 = m/s2. Area 1 m2 = 104 cm2 = 106 mm2 = 10 6 km2 1 m2 = 1550 in2 = f t2. 1 f t2 = 144 in2 = m2. Densidad 1 g/cm3 = 1 kg/L = 1000 kg/m3 1 g/cm3 = lbm/f t3 = lbm/in3. 1 lbm/in3 = 1728 lbm/f t3. 1 kg/m3 = lbm/f t3. Energ a 1 kJ = 1000 J = 1000 N m = 1 kP a m3 1 kJ = Btu 1 kJ/kg = 1000 m2 /s2 1 Btu = kJ. 1 kW h = 3600 kJ = psia f t3 = lbf f t 1 cal = J 1 Btu/lbm = 25, 037 f t2 /s2 = kJ/kg 1 IT cal = J 1 kJ/kg = Btu/lbm 1 Cal = kJ 1 kW h = Btu 1 termia = 105 Btu = kJ ( ).

2 Fuerza 1 N = 1 kg m/s2 = 105 dina 1 N = lbf 1 kgf = N 1 lbf = lbm f t/s2 = N. Flujo de calor 1 W/cm2 = 104 W/m2 1 W/m2 = Btu/h f t2. Coe ciente de transferencia de calor 1 W/m2 C = 1 W/m2 K 1 W/m2 C = Btu/h f t2 F. Longitud 1 m = 100 cm = 1000 mm = 106 m 1 m = in = f t = yd 1 km = 1000 m 1 f t = 12 in = m 1 milla = 5280 f t = km 1 in = cm Masa 1 kg = 1000 g 1 kg = lbm 1 ton metrica = 1000 kg 1 lbm = kg 1 onza = g 1 slug = lbm = kg 1 ton corta = 2000 lbm = kg Potencia 1 W = 1 J/s 1 kW = Btu/h 1 kW = 1000 W = hp = lbf f t/s 1 hp = kW 1 hp = 550 lbf f t/s = Btu/s = Btu/min = Btu/h = kW. 1 hp caldera = 33, 475 Btu/h 1 Btu/h = kJ/h 1 ton de ref rigeracion = 200 Btu/min Presi n 1 P a = 1 N/m2 1 P a = 4 psia 1 kP a = 103 P a = 10 3 M P a = lbf /f t2.

3 1 atm = kP a = bars 1 psi = 144 lbf /f t2 = kP a = 760 mm Hg (0 C) = 760 torr 1 atm = psia = in Hg (30 F ). = kgf /cm2 = m 1 in Hg = kP a 1 mm Hg = kP a DIMENSION METRICO METRICO/INGLES. Calor espec co 1 kJ/kg C = 1 kJ/kg K 1 Btu/lbm F = kJ/kg C. 1 Btu/lbmol R = kJ/kmol K. 1 kJ/kg C = Btu/lbm F. = Btu/lbm R. Volumen espec co 1 m3 /kg = 1000 L/kg = 1000 cm3 /g 1 m3 /kg = f t3 /lbm 1 f t3 /lbm = m3 /kg Temperatura T (K) = T ( C) + T (R) = T ( F ) + = (K). T (K) = T ( C) T ( F ) = T ( C) + 32. T ( F ) = T (R) = T (K). Conductividad t rmica 1 W/m C = 1 W/m K 1 W/m C = Btu/h f t F. Velocidad 1 m/s = km/h 1 m/s = f t/s = mi/h 1 mi/h = f t/s 1 mi/h = km/h Volumen 1 m3 = 1000 L = 106 cm3 1 m3 = in3 = f t3.

4 = gal(U S). 1 U S galon = 231 in3 = L. 1 f l onza = cm3 = L. 1 U S galon = 120 f l onzas Flujo volum trico 1 m3 /s = 60, 000 L/min = 106 cm3 /s 1 m3 /s = 15, 850 gal/min (gpm) = f t3 /s = f t3 /min (cf m). Viscosidad 1 P oise(P ) = 1 g/cm s = kg/m s 1 slug/f t s = kg/m s 1 P a s = 1 kg/m s 1 lbm/f t s = lbf s/f t2. Constantes f sicas Constante universal de los gases Ru = kJ/kmol K. = kP a m3 /kmol K. = bar m3 /kmol K. = L atm/kmol K. = Btu/lbmol R. = f t lbf /lbmol R. = psia f t3 /lbmol R. Aceleraci n de la gravedad est ndar g = m/s2. = f t/s2. Presi n atmosf rica est ndar 1 atm = kP a = bar = psia = 760 mm Hg (0 C).

5 = in Hg (32 F ). = m H2 O (4 C). Constante de Stefan-Boltzmann = 8 W/m2 K 4. = 8 Btu/h f t2 R4. Constante de Boltzmann k = 23 J/K. Velocidad de la luz en el vac o co = m/s = f t/s Velocidad del sonido en aire seco (0o C y 1 atm) c = m/s = 1089 f t/s Calor de fusi n del agua (1 atm) hif = kJ/kg = Btu/lbm Entalp a de vaporizaci n del agua (1 atm) hf g = kJ/kg = Btu/lbm