air gap

1. Heat Transfer through multiple walls

Hi guys, I am newbie on thread and currently working on a project I need some help on the Heat flow on multiple walls. Here is the setup (see figure below) The first wall is a Steel material which has a 350C temperature(1kwatts) and the an Air Gap is present then followed by a Plastic wall...
2. What's about no air-gap in motors?

Hi, I saw few threads here about air-gap in motors, and I wonder what if we ignore mechanical issues and make an "iron-gap" in the motor. for example: in linear motor(e.g. this cute one: https://www.physicsforums.com/threads/linear-motor-equations.794499/) if we make the tube between the stator...
3. Calculating the B field in a small gap in a toroid

1. Homework Statement Take a steel core (K_m = 2500) electromagnet, bend it into a loop with a small air gap, and determine the B field in the gap. The cross-sectional area of the toroid is 4cm^2, and the air gap is 2.5mm. The current through the coil's 120 turns is 15 amps. The radius of...