Recent content by Glenn Alexander

  1. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    Thanks Billy. Designing to the heatsink was not my origional intent but as I have set particular physical constraints and forms on my design, heat management has turned out to be the dominant factor, so I am having to limit everything else to that factor. I will look into the resources...
  2. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    No no and NO. This does not even try to answer the question I am posing. I origonally phrased my question in generalised textbook terms (which got me shouted at) to avoid just this sort of tangent-shooting faffing about. I want an answer to a particular question: how many watts can I put into my...
  3. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    Overall Heat Transfer Coefficient seems to be the next bit of the puzzle. I'm only getting an extra 3W for that, which is nice, but not that significant. Total is now about 11W per plate accounting for OHTC and Radiation. I'll call it 10W for my purposes.
  4. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    I know exactly what heat output is generated by every potential chip. I am not building a system anything like what is commercially available (if it was commercially available I would go out and buy it!) In the abscence of any other information, I have to cludge whatever data I can get together...
  5. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    I worked it out, I think. The problem was simply I didn't know the formal technical term for what I wanted to know. Once I learned it was 'Emissivity' a quick websearch for this value for common items (such as unpolished - or deliberately micro-roughened - SS) and a Stefan Boltzmann Law...
  6. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    Thanks, that sounds exactly like what I am looking for - just a rough idea of if my idea is even feasable. - An assumption of uniform heat generation in the cylinder is fine. I can install short center-to-edge heat-pipes to improve internal-to-external heat transfer too if needed. - The...
  7. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    I am happy to assume that the ambient air is able to refresh itself adequately to remain at 25degC. I am leaving myself quite a bit of leeway setting my target block temp at 50degC anyway. No reason to be overly precise - I just don't want to melt the CPU after an hour of flat-out operation (or...
  8. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    The air-facing surface is vertical. No obstructions above, below or before the surface for at least a few decimetres. (It is a silce from the middle a larger cylinder - the other parts of the cylinder can be considered thermally isolated (they won't be, but I want to treat this as if they were -...
  9. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    I am basically machining a cavity into a 168mm diameter, 21mm height stainless steel cylinder to hold a small board (possibly an intel NUC, or if that is too hot, an O-droid-UX, or an upcoming 300W AMD APU in dreamland :-) ). The top and the bottom of the disk will not be in contact with air...
  10. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    Fine. But I am not doing homework. I am wanting to embedd a CPU in a solid block of SS and want to know what TDP CPU I can get away with. (If it sounds like a homework question, blame it on my former life as a primary school teacher!)
  11. G

    Maximizing Heat Dissipation for a Stainless Steel Block in Contact with Air

    I am having trouble finding a general answer for this - search engine throws up lots of specific cases that don't quite match my needs. It is probably pretty basic but IANAE! I have a polished bare metal stainless steel block with 100 square cm surface in contact with air at a maintained...
Back
Top