Add

Mass additional ratio to Air (mass%)

Greek letters

C

Specific heat (J/(kg∙K))

α

Heat transfer coefficient (W/(m²∙K) )

D

Depth (m)

ν

Kinematic viscosity (m²/s)

G

Mass (kg)

θ

Rotation angle (rad)

H

Height between displacer piston and heat transfer surface (m, mm)

λ

Thermal conductivity (W/(m∙K) )

L

Length (m)

Subscripts

N

Number of revolutions (rpm)

0

Initial

Nu

Nusselt number (-)

air

Air

P

Pressure (kPa)

c

Cycle process

ΔP

Pressure difference (kPa)

d

Diethylether

Pr

Plandtle number (-)

DP

Displacer pinton

q

Exchange heat per time (J/s)

e

End of process

Q

Exchange heat on heating process (J/process)

h

Heat transfer surface

S (=W_h × D)

Area of heat transfer surface (m²)

i

Data step

St

Stroke (60 mm)

m

Mean

t

Time (s)

max

Maximum

T

Temperature (˚C)

pr

Process

ΔT

Temperature difference of heat source (K)

th

The oritical

u

Mean velocity on heat transfer surface (m/s)

v

Constant volume

W

Width (m)

w

Working fluid (Air, Air + PCM)