Post by qswitched on Jul 30, 2016 17:07:08 GMT
Some of the ship designs do use decane instead of methane. It ends up being a little under twice the density of methane, while yielding about 1 km/s less exhaust velocity. It's a bit of a toss up which is ultimately better, which is why both were used for various ship designs. Ultimately, methane ends up somewhat cheaper, so most of the designs used that.
Using the armor as a giant radiator has a huge number of issues. One is that you'll likely have to get rid of the Whipple Shield, because the radiators for most nuclear reactors run much hotter than the melting point. Alternatively, you need much more expensive materials, which is at odds with the point of the Whipple Shield. Regardless, the Whipple Shield is often the first thing to go in combat, which means if they are your radiators, they'll get shot immediately. This same sort of issue occurs with your main armor as well. If you put your coolant pipes near the surface of the armor, they'll work best, but they'll also get damaged as soon as you suffer hits. If your coolant pipes are at the back of the armor, they'll survive damage much longer, but the heat transfer across the armor will be abysmal, and your radiator efficiency will suffer immensely (especially if you're talking 10+ cm of armor that the heat needs to transfer across).
In the same vein, even if the pipes are near the back of the armor, damage to the front of the armor often causes spallations and other damage all throughout the bulkhead. This means any damage at all has the possibility of wrecking your coolant pipes. Generally, separate radiators have the advantage of being smaller, and can be aimed edge-on at the enemy to reduce their cross section, and thus, greatly reduce the enemy's ability to hit them.
But the biggest issue is that material strength decreases with temperature. If the bulkhead cooling your reactor is 1200 K, you have a giant, glaring weak point on your ship, sure to attract all sorts of fire.
A tighter armor cross section would save on mass for sure. It is a bit tricky, however, because the propellant tanks and the compartments in general vary with differing shapes along the length of the ship. For instance, going from six tanks to four (which is fairly common), would require geometric discontinuities between the sections which might be minor weak points.
About the angled armor, a full cylinder would have the best slope, as only a small section would be close to 0 degrees. With the rounded prisms, anytime the enemy is side-on, a full section of the ship is close to 0 degrees. And when the enemy is barraging your ship with thousands of projectiles, having such a large weak spot is a problem. Even if it means the adjacent sections are better armored, having one section which is poorly armored is a problem, as armor is usually only as good as it's weakest point.
Using the armor as a giant radiator has a huge number of issues. One is that you'll likely have to get rid of the Whipple Shield, because the radiators for most nuclear reactors run much hotter than the melting point. Alternatively, you need much more expensive materials, which is at odds with the point of the Whipple Shield. Regardless, the Whipple Shield is often the first thing to go in combat, which means if they are your radiators, they'll get shot immediately. This same sort of issue occurs with your main armor as well. If you put your coolant pipes near the surface of the armor, they'll work best, but they'll also get damaged as soon as you suffer hits. If your coolant pipes are at the back of the armor, they'll survive damage much longer, but the heat transfer across the armor will be abysmal, and your radiator efficiency will suffer immensely (especially if you're talking 10+ cm of armor that the heat needs to transfer across).
In the same vein, even if the pipes are near the back of the armor, damage to the front of the armor often causes spallations and other damage all throughout the bulkhead. This means any damage at all has the possibility of wrecking your coolant pipes. Generally, separate radiators have the advantage of being smaller, and can be aimed edge-on at the enemy to reduce their cross section, and thus, greatly reduce the enemy's ability to hit them.
But the biggest issue is that material strength decreases with temperature. If the bulkhead cooling your reactor is 1200 K, you have a giant, glaring weak point on your ship, sure to attract all sorts of fire.
A tighter armor cross section would save on mass for sure. It is a bit tricky, however, because the propellant tanks and the compartments in general vary with differing shapes along the length of the ship. For instance, going from six tanks to four (which is fairly common), would require geometric discontinuities between the sections which might be minor weak points.
About the angled armor, a full cylinder would have the best slope, as only a small section would be close to 0 degrees. With the rounded prisms, anytime the enemy is side-on, a full section of the ship is close to 0 degrees. And when the enemy is barraging your ship with thousands of projectiles, having such a large weak spot is a problem. Even if it means the adjacent sections are better armored, having one section which is poorly armored is a problem, as armor is usually only as good as it's weakest point.