Analysis of Heat Transfers inside Counterflow Plate Heat Exchanger Augmented by an Auxiliary Fluid Flow

Table 1

The used fixed dimensions and the properties of different substances.

Property	Hot fluid	Cold fluid	Auxiliary fluid	Auxiliary fluid
	Engine oil	Water	Air	Air
𝑇1 (°C)	80	15	31.25 (𝑆=0.25)	47.5 (𝑆=0.5)
𝑐𝑝 (𝐽 kg^−1 K^−1)	2132	4186	1007	1008
𝑘 (𝑊 m^−1 K^−1)	0.138	0.595	0.0266	0.0278
𝜇 (kg m^−1 s^−1)	0.0323	1.134×10^−3	1.867×10^−5	1.943×10^−5
𝜌 (kg m^−3)	852	999	1.228	1.101
Dimension	Hot flow channel	Cold flow channel	Dimension and property	Pins
𝐻 (mm)	2	3	𝑑𝑓 (mm)	2
𝑊 (mm)	48	48	𝑘𝑓 (𝑊 m^−1 K^−1)	401
𝐿 (mm)	200	200	𝑢∞ (m s^−1)	25
(𝑆=0.25)	(𝜙ℎ,𝑐)Min=(0.04308,0.02997)Pe𝑐,ℎ−117.028/𝑎𝑓−1
(𝑆=0.5)	(𝜙ℎ,𝑐)Min=(0.06668,0.01547)Pe𝑐,ℎ−116.966/𝑎𝑓−1