You have been asked to perform a feasibility study on the design of a blood warmer to be used during the transfusion of blood to a patient. This exchanger is to heat blood taken from the bank at 10°C to 37°C at a flow rate of 200 ml/min. The blood passes through a rectangular cross-section tube, 6.4 mm by 1.6 mm, which is sandwiched between two plates held at a constant temperature of 40°C.

(a) Compute the length of the tubing required to achieve the desired outlet conditions at the specified flow rate. Assume the flow is fully developed and the blood has the same properties as water.

(b) Assess your assumptions and indicate whether your analysis over- or underestimates the necessary length.

Plate at 40C Tube Uniform temperature plates 1.6 mm +| 6.4 mm Front view (with one plate removed) Side view Tube