A circular transistor of \(15-\mathrm{mm}\) diameter is cooled by impingement of an air jet exiting a 3-mm-diameter round nozzle with a velocity of \(20 \mathrm{~m} / \mathrm{s}\) and a temperature of \(15^{\circ} \mathrm{C}\). The nozzle exit and the exposed surface of the transistor are separated by a distance of \(15 \mathrm{~mm}\).

If the transistor is well insulated at all but its exposed surface and the surface temperature is not to exceed \(85^{\circ} \mathrm{C}\), what is the transistor's maximum allowable operating power?

Transcribed Image Text:

Air jet Transistor