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Thermodynamics / Heat Transfer, physics homework help

QUESTIONS:

** SHOW ALL WORK AND JUSTIFY METHOD BY SHOWING EQUATION DERIVATION **

** SHOW ENERGY BALANCE AND INCLUDE RADIATION AND CONVECTION EFFECTS **

A SILICONE PAD IS MOLDED TO AN ALUMINUM DIE THAT IS CONNECTED TO A BASE. THAT BASE IS FASTENED TO AN ALUMINUM BLOCK WITH A HEATING ELEMENT IN THE CENTER  THAT CAN PRODUCE QGEN  MAXIMUM OF  700 W. THE ALUMINUM HEATING ELEMENT BLOCK IS CONNECTED TO A STAINLESS STEEL SUPPORT STRUCTURE THAT ACTS AS A HEAT SINK.

1. WHAT IS THE OPTIMAL THERMAL CONDUCTIVITY OF SILICONE PAD?

2. HOW LONG DOES IT TAKE THE ALUMINUM SYSTEM TO GET TO STEAD-STATE?

3. HOW LONG DOES IT TAKE FOR THE SILICONE PAD TO REACH STEADY-STATE? SHOW ENERGY BALANCE AND INCLUDE RADIATION AND CONVECTION EFFECTS.

4. THE PAD NEEDS MAKES CONTACT WITH A POLYESTER SUBSTRATE  (HEAT SINK ) OF SAME AREA AND MUST REMAIN IN CONTACT FOR 30 SECONDS. ASSUMING HEAT TRANSFER TO POLYESTER IS PURE CONDUCTION, WILL THE HEAT TRANSFER BE SUFFICIENT TO EXPOSE THE SUBSTRATE TO A CONSTANT 118 C IN ORDER TO CURE? IF NOT, WHAT NEEDS TO BE CHANGED AND HOW?

ASSUMPTIONS:

START TEMPERATURES = 25 C

CONVECTION & RADIATION EFFECTS NEED TO BE INCLUDED

– (USE SIDE AREA FOR ALUMINUM ALL )

– (USE ALL AREA FOR SILICONE)

MAX TEMPERATURE TD = 200 C

MAX TEMPERATURE Ts =  118 C

AIR TEMPERATURE T0 =  25 C

Q gen = 700 W

ADDITIONAL AREA AND LENGTH VALUES FOR EACH COMPONENT SHOWN IN POWER POINT