# Simulation Quiz 2

### Thermal Radiation in an Oven

An oven achieves the goal of cooking food through various heat transfer mechanisms.  One such mechanism is radiation from the hot broiler elements on the top of the oven to the food below.  In this problem, we will examine the heating of food from the broiler heating element. A simplified electric oven model will be used for this simulation.  The oven is set up to simulate the radiative heat transfer from the cooking element to the food.  Although important in real life, convective heat transfer inside the oven is omitted for purposes of this exercise.

Follow instructions to set up the simulation and get results BEFORE starting the quiz. Download the instructions and necessary simulation files from here.

Note: The Expected Completion Time for this quiz is 15 mins but, the Maximum Available Time to complete the quiz is 30 mins.

#### Total Number of Questions - 10

Times up!

Heat Transfer for Structures - Simulation Quiz 2

Complete the simulation and have all the results ready BEFORE starting the quiz.

Once you have finished the exam, click on the 'Mark Complete' button to save your progress and move to the next section.

1 / 10

In System C (“Open Door with Food”), the maximum temperature of the food is _____.

2 / 10

In System C (“Open Door with Food”), the maximum temperature of the heating element is _____.

3 / 10

In System B (“Food Wrapped in Foil”), compare the absorbed radiative heat flow rate of the food (Emitted Radiation) to the net radiative heat flow rate (Outgoing Net Radiation) of the heating element. What fraction of the heat flow rate from the heating element is being absorbed by the food? (Recall that absorbed radiation = emitted radiation for bodies in thermal equilibrium.)

4 / 10

The food has a high emissivity and hence low reflectivity. In System A (“Closed Door with Food”), what is the reflected heat flow rate (Reflected Radiation) of the food?

5 / 10

In System A (“Closed Door with Food”), the grill is a shiny metal and has low emissivity. Thinking about this and the equation $\tau+\alpha+\rho = 1.0$ with transmissivity $\tau$ = 0, what is the reflectivity ($\rho$) of the grill.

6 / 10

In System B (“Food Wrapped in Foil”), the maximum temperature of the heating element is _____.

7 / 10

Ignore the interior convective heat transfer, as we have done in this simulation, and compare the maximum temperature of the food in System C (“Open Door with Food”) with the maximum temperature of the food in System A (“Closed Door with Food”). Which best reasonable conclusion can be drawn?

8 / 10

The food has a high emissivity and hence absorptivity. In System A (“Closed Door with Food”), what is the absorbed heat flow rate (Emitted Radiation) of the food? (Recall that absorbed radiation = emitted radiation for bodies in thermal equilibrium.)

9 / 10

In System B (“Food Wrapped in Foil”), the food with the aluminum foil has a low emissivity and hence high reflectivity. What is the reflected heat flow rate (Reflected Radiation) of the food?

10 / 10

In System A (“Closed Door with Food”), looking at the temperature distribution on the food body only, why does temperature distribution show the food is hotter on the +Y side versus the –Y side.