Engineering, 18.10.2019 21:00 HecptyAura

The convection coefficient for flow over a solid sphere may be determined by submerging the sphere, which is initially at 25 °c, into the flow, which is at 75 °c, and measuring its surface temperature at some time during the transient heating process. if the sphere has a diameter of 0.1 m, a thermal conductivity of 25 w/(mk), and a thermal diffusivity of 2.0 x10 m2/s, at what time will a surface temperature of 60 oc be recorded if the convection coefficient is 300 w/(m 2 .k)? 1: when deciding if the lumped capacitance method can be used, what is the value of the biot number? bic=? 2: when using the one-term approximation for transient 1-d conduction, what is the value of the applicable biot number? use table 5.1. bi=? 3: using the one-term approximation, if bi in table 5.1 were equal to 0.5, what would be the value of for this problem? c1=? 4: use the one-term approximation method to solve for the fourier number. fo=? 5: solve for the time required for the surface of the sphere to reach 60 °c, in sec. t=_seconds.

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