TABLE II.

Heat Transfer Parameters

Parameters	Symbols	Units	Values
SMA spring wire
Wire diameter	ds	m	0.75 × 10−3
Coil diameter	Ds	m	6.5 × 10−3
Resistivity	βs	μΩ·m	0.44
Density	ρs	kg/m3	6450 [29]
Thermal conductivity	ks	W/(m·K)	18 [30]
Specific heat capacity	Cs	J/(kg·K)	466 (heating) −260 (cooling)
Latent heat (heating)	Lsh	J/kg	12188.1
Latent heat (cooling)	Lsc	J/kg	−4137.6
Air
Temperature	Ta	K	300
Thermal conductivity	ka	W/(m.K)	0.0263
Expansion coef.	βa	1/K	3.43 × 10−3
Kinematic viscosity	νa	m2/s	15.89 × 10−6
Thermal diffusivity	αa	m2/s	22.5 × 10−6
Water
Temperature	Tw	K	300
Prandtl number	Pr	-	5.83
Thermal conductivity	kw	W/(m.K)	0.613
Kinematic viscosity	νw	m2/s	8.6 × 10−7