Simple Stirling Engines built from the plans

Occasionally I hear from others who have built the simple Stirling engine from my plans. Most people end up making some kind of modifications to the plans. That’s fine with me, in fact I enjoy seeing how other people solve a problem. The only area where experimentation could be risky (in terms of ending up […]

Power Piston Sizing

Engine 3F sim

How big should your Stirling engine power piston be? (Be sure to see my more recent post on power piston sizing. It provides more specific information. — Doug Conner) A common problem Stirling engine designers face is how much volume should the power piston sweep in comparison with the displacer? This of course only applies […]

Engine 3F Efficiency Analysis part 4

Rev 1: See details at bottom. Let me summarize what has been covered and what remains in this efficiency analysis: Component Power percentage of total power Efficiency analysis Heat lost directly to the environment 40.3w 58.4% Part 1 Thermal shorting: heat conduction directly from the hot end to the cold end 5.9w 8.6% Part 2 […]

Engine 3F Efficiency Analysis part 3

Let me summarize what has been covered and what remains in this efficiency analysis: Component Power percentage of total power Efficiency analysis Heat lost directly to the environment 40.3w 58.4% Part 1 Thermal shorting: heat conduction directly from the hot end to the cold end 5.9w 8.6% Part 2 Gross engine power: includes net shaft […]

Engine 3F Efficiency Analysis part 2

Continuing with the analysis of where the input power (heat) to the engine goes, the next item to consider is the conduction loss often referred to as thermal shorting. Conduction losses A Stirling engine of gamma configuration, such as the one being considered, uses a displacer to shuttle the operating gas back and forth between […]

Engine 3F Efficiency Analysis part 1

In an earlier post I measured 1.05 watts output from my engine 3F using a 69 watt input. This computes to 1.5% efficiency. So where did the other 68 watts go? The following is my analysis of where all the energy went. It won’t be as rigorous as I would like, partly due to lack […]

Measuring a Stirling engine with 1 watt power output and 1.5% efficiency

The following is a transcript with still photos of the previous video on the same subject. I’ve included a few more notes about the engine, my model 3F. This is a gamma configuration Stirling engine. I’m powering it with the heat from a 70 watt light bulb so that I can accurately measure the heat […]

Measure the power and efficiency of your Stirling engine; it’s easy

In the world of small Stirling engines everyone seems to talk about power and efficiency—but you seldom see the facts and the data. Just a couple days ago I saw the following Stirling engine on Youtube: The promoter claims it must be putting out 100 to 150 watts. It was the usual unloaded engine spinning […]

Stirling Engine Simulator & Guide

The Stirling engine simulator is a simple isothermal cycle simulator for Stirling engines. The guide below should be helpful to those interested in using the simulator. Although it’s a fairly simple simulator, you can learn a lot about Stirling engine design by trying out different designs and operating conditions. What is it? The Stirling engine […]

Ideal Stirling Cycle Spreadsheet

  This Excel 2003 spreadsheet stirling-cycle-ideal-v-02 lets you input the basic values for a Stirling cycle engine and calculates various quantities such as pressures, work in, work out, heating, cooling, and ideal efficiency. Don’t use this spreadsheet with the idea that your engine will get close to the values it shows unless you have an […]