Heisler Charts
General methodology for using the charts in chapter 9-2:
Use a plane wall of thickness 2L as an example
- Use figure 9-13(a) to determine the midplane temperature as a function of time: TO=T(x=0,t) for given Biot numder
- Use figure 9-13(b) to determine the temperature distribution T(x,t*) at a given point x and a given time t* by relating to the midplane temperature at the given time, TO(t*). That is, to determine (T(x,t*)-T?)/(TO(t*)-T?) for given x/L using figure 9-13(b)
- Internal energy change should first be calculated: QO=rcV(Ti-T?). Based on this, the total heat transfer at a given time, Q, can be determined from figure 9-13(c) at a given Biot number by finding Q/QO. A new variable Bi2t is used to represent the time variation.