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#76 2020-12-28 07:44:40

tahanson43206
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Registered: 2018-04-27
Posts: 7,981

Re: Internal combustion engines for Mars

For SpaceNut re #75

Following up ... you've covered a LOT of ground in post 75, and this post is intended to be a short appreciation and suggestion.  The constant-flowing-under-the-bridge nature of a forum like this one means that for your dense collection of information to be quickly found when a reader wants to find it, it would be helpful to have tags.

I have been trying to show what tags would look like, when I add them in separate posts for kbd512 or GW Johnson.

In this case, I'd like to invite you to add tags to that post to help find it weeks or months from now.

At the moment, fresh from rereading the post, I know it is contained in the IC topic which is in Planetary Transportatation, and it is by SpaceNut.

What is needed (from my perspective) is a tag that is easy to remember and which is sufficiently unique that it will help your post stand out.

***
As some time has gone by since your originally worked on the material collected in the post, this topic has shown the need for an oxidizer to be supplied to any IC engines designed and manufactured for Mars.  You could (if you had time) add a few lines about collecting and storing Oxygen for the machines you've described in the post.

In any case, thanks for the details of energy quantities, chemical formula and quantities of material of various kinds relating to your theme.

(th)

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#77 2020-12-28 08:05:45

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re development of this topic …

This topic started out as you were inspired by your study of a Subaru motor.

Reverse Engineering is a time honored way of pulling embodied knowledge from an artifact.

Forward Engineering is how the artifact (the Subaru motor in this case) came into being.  But the finished artifact includes trial and error, which is the inevitable companion of Forward Engineering.

I'd like to invite you to turn this topic into an activity that yields a complete documented infrastructure for Mars.  You could (if you had the time and energy) take measurements of the engine you're repairing.  Those measurements could be translated into 3D Printer command files that could deliver plastic mockups of parts for evaluation, and metal parts for implementation in the field.

The unending argument about the advantages and disadvantages of electrical equipment compared to IC equipment have no place in this topic.  What is needed is FOCUS … this topic can (and in my opinion) should, yield a set of plans that an enterprising group can implement successfully on Mars.

The electricians have their own topic, and I'd like to see them develop it in exactly the same way.

In ** that ** topic, specifications for an all-electric solution for the on-Mars construction problem could be (and in my opinion, should be) posted, tried on Earth, and implemented on Mars after a bit of trial and error.

(th)

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#78 2020-12-28 08:30:55

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 23,826

Re: Internal combustion engines for Mars

As we have done in the topic was come up with some of the constraints for why would we want an engine for mars.

Post #65 gave the electrolysis which yield oxygen from a water source which is argued to be 25 times greater than from the atmosphere for the same energy embodied sure since its not at the same density of volume it would.

In posts #71 -#73 We have talked about the issue of storage in rocket tanks which have a boiloff issue requiring preventative measures with cryocoolers for not only the Oxygen and Hydrogen to allow for a build up of quantity for a starship is huge. To which add in a few pumps to pressurize as its cooled.

Temporary tanks mentioned for collection of exhaust or gaseous outputs until we cool to liquid levels in post #74 which if not separated can be direct fed into the inlet for the engine to use as Brown gas or HHO. We talked about the need to moderate temperatures in the cylinders in post #44 with turbo compressed co2 plus other posts, to which would show in the exhaust as another means to collect it at concentrations for other processes to recycle back into oxygen, carbon and hydrogen.

Tank size for mobile use discussions on ratio based mileage or hours of use still to be determined for the engine and ignition type to be deployed. Fixed type engine use at a minimum is manipulating boiloff via regulators to control inlet pressures and espansion tanks to temporary hold it safely.

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#79 2020-12-28 10:28:54

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re #78

From your summary of the history of this topic and related ones, it would appear (as I see it) that we (forum members and readers) are in position to start making hardware capable of successful operation on Mars.  It is even possible to develop plans and procedures for manufacture of all that hardware ON Mars, using locally sources materials, supplemented with a bit of import from off-Earth locations such as Titan.

This forum format needs to be supplemented by online services that stay in one place and do not constantly flow under the bridge and out of view.

There could be an online location where the specifications of an engine to be fabricated on Mars using locally sourced materials could be described in detail down to the precision needed for each applications.

Discussions here can continue to thrash out all the options before someone makes a decision and sets the specifications for components.

Once a particular specification has been set in place, everything else flows from that according to Nature's Laws.

RobertDyck provides a helpful example of the kind of leadership I'm talking about.

RobertDyck pulled numbers from his experience and his knowledge of physics, and his knowledge of human physiology, to set the parameters for what I am confident will eventually be a fleet of sturdy vessels plying the Earth/Mars trade.

This topic needs a similar set of specifications.  They can be pulled from existing Earth examples, or created without an example.

Once those crucial first specifications are set in place, folks can be enlisted to add to the set of knowledge that will ultimately be embodied in actual hardware shoving regloith on Mars.

(th)

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#80 2020-12-28 20:02:53

SpaceNut
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From: New Hampshire
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Re: Internal combustion engines for Mars

Squirely computer so doing stealth mode bombing of topic with references on engines

https://en.wikipedia.org/wiki/Internal_ … ion_engine

simular definitions
https://www.theengineerspost.com/intern … n-engines/

most performance and emissions
https://www.energy.gov/eere/vehicles/ar … ine-basics

https://learnmechanical.com/internal-combustion-engine/

According to all the speed of the engine -

Low-speed engine-N < 300 RPM
Medium speed engine- 500<N< 1000 RPM
High-speed engine - 3600<N< 6000 RPM

Of course we will not be running that high in RPM's

What is Turbocharger?

By this device, a large amount of energy within the exhaust gas is used for other purposes. The outgoing exhaust gas is allowed to expand in a nozzle and a huge quantity K.E. is obtained which is used to drive the exhaust gas turbine.

The exhaust gas turbine is used to drive the supercharger. Combination of a supercharger and exhaust gas turbine is called turbocharger.

https://en.wikipedia.org/wiki/Turbine

turbo-3638880_640-300x266.png

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#81 2020-12-28 20:59:47

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re Post #80

Picking up on your closing section of the post ... exhaust gas from an IC on Mars ...

Unlike on Earth, the exhaust would be to a near vacuum ... that implies (as I understand the situation) that the efficiency/effectiveness of the exhaust gas would be greater than would be the case on Earth.   There may be a member of the forum who can provide numbers to go with the suggestion .... I had been assuming that if we drive a piston using CO/O2/CO2 then we'd have accomplished about as much as might be expected, but perhaps tapping the exhaust to the atmosphere will allow collection of even more energy.  In this case, the energy collected would presumably be fed back into the intake side of the system.

Per GW Johnson's reminder earlier in this topic, the input to the cylinders needs to be at or above Earth standard sea level pressure.

(th)

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#82 2020-12-28 21:27:52

SpaceNut
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From: New Hampshire
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Posts: 23,826

Re: Internal combustion engines for Mars

co2 is drawn in from the turbo's motion as caused by the exhaust cycle. It would want to be collected and not allowed to escape to open mars but t be able to build up a larger volume of co2 for other uses in a capture system. So the question is a drop tank that gets filled with the high pressure co2 which the machine is creating or some sort of expandable bag that can float above the vehicle as it fills.....

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#83 2020-12-29 05:32:05

kbd512
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Posts: 4,893

Re: Internal combustion engines for Mars

tahanson43206,

I used a specific example based upon an Earth-bound vehicle well-known for its durability in combat environments.  It's a T-55 tank chassis that serves as a bulldozer here on Earth.  It has all the attributes of a good bulldozer.  Specifically, it has good traction, low-CG, high power-to-weight ratio, low deck height that allows an operator to mount / dismount the vehicle easily without the use of hand-holds, superb protection from the environment, and durable moving parts that have endured through many decades of service.  I was very specific about how much it weighs, both here on Earth, and how much it would likely weigh on Mars after being retrofitted into a Mars-specific bulldozer configuration.

We would likely NOT use the same types of steels used in Earth-bound vehicles.  To deal with the wild daily temperature swings and potential for corrosion from salts in the regolith, we need a chassis / track links / running gear made from stainless steels.  That steel will be further protected from corrosion and abrasion through the application of a very tough ceramic-based coating such as CeraKote.

MATERIALS FOR CRYOGENIC SERVICE: ENGINEERING PROPERTIES OF AUSTENITIC STAINLESS STEELS

A 1.25" thick by 48" wide x 144" long plate of 304 stainless is approximately $14.6K:

Midwest Steel Supply - 304 Stainless Plate

304 has good weldability.  We could use automated MIG welding techniques to produce excellent results.  It should be case hardened / nitrided, rather than through-hardened like plate armor, to better accommodate flexure without suffering from fatigue cracking.

The entire vehicle chassis will be coated, inside and out, with an electrically non-conductive baked-on ceramic coating.

CeraKote H900 Electrical Barier ceramic Coating

The tracks should be S53, which has excellent corrosion resistance and fatigue life.  It'll be crazy expensive, but these forgings should produce very durable track links.

To save weight, the road wheels could be cerakoted billet 5083 Aluminum alloy.  It's fairly common for lighter and more modern armored vehicles to use Aluminum alloy road wheels instead of steel.  The M113 is almost entirely 5083 alloy, for example.  Even if we ultimately use batteries, this vehicle would be significantly lighter on the moon or Mars, so the weight presents less of an ultimate durability issue.  Either way, Thoraeus metallic rubber will be the compound used to wrap the road wheels, since it's likewise capable of withstanding use in mildly cryogenic environments.  5083 was originally created for use in cryogen tanks, but replaced low alloy steel armor in the M113 series because it was effective for the intended use and it was lighter than steel.  Similarly, our LOX / LCO vacuum thermos tanks will be 5083 Aluminum alloy with a fluoropolymer or ceramic coating, neither of which should not have adverse interactions with LOX or LCO.

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#84 2020-12-29 07:09:42

tahanson43206
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Re: Internal combustion engines for Mars

For kbd512 re #83 of IC topic ...

I ** like ** it ... The system ** should ** work:

a) On Mars or the Moon, both of which are going to need plenty of regolith movment
b) With remote control by human operators or potentially by AI operators when the reach that stage of development

SearchTerm:TankChassis Bulldozer design for Mars or Moon

http://newmars.com/forums/viewtopic.php … 70#p175370

Can I invite you to develop your ideas a bit further?  What I'm looking for is an outline of how vehicles like this might be manufactured ON the Moon or Mars, using indigenous materials?

For quite some time, it seems to me humans are going to need to bring their own energy supplies, so for discussion, let's assume nuclear reactors are available to provide power.

A bootstrap operation to build vehicles like the one you've described in a continuous flow would need to arrive on site with some minimal set of equipment and capability. 

I'm planning to create a post in the Electric topic, to see if I can encourage someone to take your concept and run with it there.

Nice work!

(th)

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#85 2020-12-29 07:41:53

kbd512
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Re: Internal combustion engines for Mars

tahanson43206,

There won't be any manufacture of construction equipment on the moon or Mars within the next 20 years or so.  That requires heavy industry that only an advanced human civilization could create.  In other words, a city of a million people would have to pre-exist on those planetary bodies.  Let's worry about building the habitable living space first, using realistic construction equipment that we actually know how to make, before worrying about how we'll make heavy construction equipment there.  There was no heavy construction or mining equipment prior to industrialization.  We're starting from scratch, same as we did during the industrial revolution.  We need suitable transport, life support, agriculture, pressurized habitable living spaces, and construction equipment to build the same.  Solve the immediate problems first.  We don't have multi-MW-class nuclear reactors ready to use anywhere but Earth, either.  We can pack up and ship a CSP power plant in Starship-transportable loads.  If / when suitable nuclear reactors are developed, I would agree that they make all other aspects of implementing a construction plan much easier, but we'll cross that bridge when we get there.

We need startup / bootstrap power that only small modular reactors can provide, so that's a top priority.  From there, we need rapid construction of a 10MW to 20MW CSP power plants that store thermal energy in molten salt or molten metal, although multiple power plants that are ideally sited to extract a necessary resource would be highly desirable.  For example, we want a power plant near a known buried glacier, another near a source of Sulfur, and probably a third wherever we intend to construct habitable living spaces.

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#86 2020-12-29 08:29:59

tahanson43206
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Re: Internal combustion engines for Mars

For kbd512 re #85

Thanks for the reminder we have to walk before we run (as individuals and as a society) ...

There is room for both near term and far term planning.   The best example I can offer is the Normandy Invasion ....

The planning team for that operation gathered the resources necessary, trained the personnel, and coordinated the operation to land a fully functional combat operation on the surface of a foreign land, and they had the enemy to contend with.

I'm interested in a Normandy Landing scale operation to set up shop on Mars.

The pre-cursor missions are going to be interesting and quite educational, but they will be roughly comparable to the information gathering flights by the brave flyers given that assignment, and by similar groups of sailors asked to explore the situation near the beaches.

The My Hacienda topic is set up to be a Normandy Scale transition of entire planned activities for 7800 people (or so) arriving in a single coordinated operation.

I try to remain flexible in thinking, so I can shift from thinking about the first or second missions to the full scale operation down the road, or whatever the space equivalent of that expression may be.

It was in light of the later operation that I inquired about planning manufacture of the vehicle.  Those who are planning now (aged 26 and under) to take part in the massive coordinated operation will need to go with all the knowledge, skills and tools (and supplies) needed to set up temporary shelter and then proceed to implement the full scale plans they've contracted to achieve.

It is in that context that I am hoping to encourage development of specific plans including drawings for the vehicle you have proposed.

(th)

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#87 2020-12-29 08:44:46

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re 82 ...

SpaceNut wrote:

co2 is drawn in from the turbo's motion as caused by the exhaust cycle. It would want to be collected and not allowed to escape to open mars but t be able to build up a larger volume of co2 for other uses in a capture system. So the question is a drop tank that gets filled with the high pressure co2 which the machine is creating or some sort of expandable bag that can float above the vehicle as it fills.....

I copied the entire post here because it is (relatively) short ...

This is an interesting idea, and I'm hoping you'll develop it further.

The refined CO2 exhaust from an IC engine on Mars (and certainly on the Moon) would be valuable.

All the work done to scavenge it in the first place, and to remove contaminants (in the case of Mars) represents energy collected by solar cells or consumed from a nuclear reactor.

My concern and question is: How are you going to store that hot gas so it can be returned to base?

You can't take energy from the dozer to compress it.  The dozer needs every one of it's 1000 horsepower to push regolith.

The dozer is already encumbered with tanks for CO/O2/CO2 (the CO and CO2 would most likely be mixed to mission requirements ahead of time).

Where would you put the exhaust gas, without consuming any of the 1000 horsepower for pushing regolith.

Kbd512 has a similar challenge over in the Electric topic.  There he is using LCO2 for coolant, and when the coolant becomes a gas it needs to be stored somehow, without consuming power for the dozer.

***
PS ... can you work up specifications for a 1000 horsepower IC engine for kbd512's dozer.  It would use CO/O2/CO2. 

You may be able to use the Subaru motor you're repairing as a guide for dimensions needed. 

(th)

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#88 2020-12-29 10:19:53

SpaceNut
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From: New Hampshire
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Re: Internal combustion engines for Mars

As I had put in the other topic we are looking at a hybrid machine for anything that moves to be partially powered by batteries while the brute force to push and lift ect.. is developed by an engine. The engine time on could be seconds to minutes but if its idling its in hybrid or electrical mode of running what must be run.

Think of a pair of folk lifts one being battery only and the other being powered by bottled gas. Both can shut off but only 1 can perform life support while off. Its the combination of the two into a single machine that provides the best of both worlds.

I think calculations have been done for running engines in another topic if its still here for fuels to exhaust....

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#89 2020-12-29 12:08:15

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re #88 .... This topic is NOT about a hybrid system ...

However, this might be a good time to set up a topic for that ...

In order to help future readers to focus on the topic itself, this topic needs to stay tightly on the IC only track.

As shown be earlier posts in this topic, it is tempting to come up with reasons NOT to build IC engine powered equipment for Mars or anywhere else.

However, this topic is specifically available to advance the state-of-the-art-of-design of IC powered equipment for Mars and other locations away from Earth.

The question brought up by your interesting proposal to harvest CO2 from the exhaust pipe needs to be addressed at some point.

Highly refined CO2 is delivered at the manufacturing site, to make CO and O2, and it is a shame to lose that pure gas when we operate the engine on Mars (or wherever else it might prove advantageous).  However, saving that exhaust gas should NOT be done at the expense of the horsepower delivered to moving the load, so I'm hoping forum members currently registered will be able to suggest ways that might be done.

(th)

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#90 2020-12-29 13:25:23

GW Johnson
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From: McGregor, Texas USA
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Posts: 4,682
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Re: Internal combustion engines for Mars

I guess my advice is simple:  when comparing energy storage,  you have to do it on not just the fuel mass or volume,  the way we traditionally do it on Earth.  On Mars you have to carry the fuel,  the oxygen,  and any diluent gas.  You compute energy storage density per unit mass or volume of that total of stored stuff. 

We get away with just looking at the fuel here on Earth,  because we have an oxygen-rich atmosphere already blended with a diluent gas.  We only have to carry the fuel.  We cannot do that on Mars.  When you look at combustion energy releasable,  per unit of the total mass or volume,  it is not so very different from battery energy densities.  But if you fail to look at it that way,  you will get quite the wrong answers for vehicle ranges on Mars,  precisely because you carry everything,  not just fuel.

And don't forget the conversion efficiency factors that scale theoretical releasable chemical energy.  For most transportation IC engines here on Earth,  these efficiencies fall in the 10-20% conversion,  of lower heating value time fuel flow rate to usable shaft power.  Lower heating value is the chemical release,  adjusted for no condensation of any water in the exhaust.  Its traditional basis is fuel mass or volume only.

Because of our Earthly prejudices,  fuel heating values are reported as theoretical chemical energy release per unit mass (or volume) of the fuel only.  So,  even those definitions are inappropriate for Mars,  because you have to carry the oxygen and any diluent gas on Mars,  as well as the fuel.  Yet the engine conversion efficiencies are still what they are. 

GW

Last edited by GW Johnson (2020-12-29 13:29:28)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#91 2020-12-29 13:41:51

tahanson43206
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Re: Internal combustion engines for Mars

For GW Johnson re #90

Thank you for your continuing support of this topic!

I ** think ** I understand what you've called for, and (for the sake of the hypothetical young person planning to use IC engines on Mars, if I could do it, I would.

What I'd like to see is a concise post that tells the (hypothetical) young Mars settler everything (they) need to know to create a viable business providing regolith moving services to customers on Mars, using IC engines running CO/O2/CO2.

Taking the example provided by kbd512 as a guide, we have an Earth-proven design for an earth moving machine.  We know the mass and dimensions of the vehicle (from posts by kbd512) and we can set a goal of being able to push with a ton of force for 8 hours.  In actual practice such a machine would push a while, then back up, reposition and push some more, but setting the straight push goal allows for an estimate of work accomplished.

Given the percentage of efficiency you've suggested (a range from 10% to 20% max) it should be possible for someone with the skills necessary to report that the vehicle described by kbd512 would require (x) CO, (y) O2 and (z) CO2 to accomplish the work required.

Given the amounts of gas that arise from the above, it should be possible to compute the volume of tankage needed.

I have no idea what that volume might amount to ... it might turn out to be ridiculous, or it might turn out to be feasible.

Meanwhile, the same calculation could be done in the Electric topic, where batteries are proposed, with the interesting feature that battery packs could be swapped out at the job site, although (to be fair) the batteries would probably not last the full 8 hour shift at 1 ton of force against the load.

(th)

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#92 2020-12-29 15:16:26

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 23,826

Re: Internal combustion engines for Mars

An Auto with an alternator and battery is a crude hybrid as its part of the structure to make its engine stay running. They also need a separate starter so why not combine the starter and alternator as a hybrid does. We do not need to use the EV motor in any of the drive modes.

This goes more power for life support function in a mobile design.

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#93 2020-12-29 18:46:41

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re #92

This is your topic.  I agree that it makes sense to plan for electrical subsystems to start an IC motor on Mars (or anywhere)

Adding a starter motor (electric) and a battery to supply it is a long way from turning the wheels with an electric motor.

The Electric topic can (presumably) do without a starter motor.

My concern was that by straying too far from the focus of this topic we were at risk of making the topic difficult for a future reader to follow.

You've added an additional element to the flow here, by hinting at the possibility of separating the life support package from the IC engine.

In an IC engine powered vehicle on Earth (in every case that I can think of right now) the IC engine supplies power for appliances in the life support capsule, as well as heat to keep the occupants warm.

Keeping the occupants warm is a nice bonus for an IC engine design for Mars.

Over in the Electric topic, the posters are going to have to allocate electric power from their batteries to keep the occupants of the life support system warm.

This advantage of the IC engine will not be lost on the designer/builder/operators.  The 10%/20% efficiency of power delivered to the crankshaft that GW Johnson forecast can be added to the 80+% efficiency of heat delivered for life support.

However, I would expect all construction equipment intended for outdoor service on Mars to be primarily remote controlled, so all that heat for the cab would not be particularly useful except on rare occasions when a human ** has ** to be present.

(th)

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#94 2020-12-29 18:57:42

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 23,826

Re: Internal combustion engines for Mars

In the old days one could actually move a vehicle with the starter motor if drive was engaged as a last ditch effort to get back to base. So redundancy is not a bad thing if seldom used....

The coolant for a mars engine is most likely ammonia due to the extreme temperatures but that still needs to be experimented with as would heater core for cab use.

Another problem with the engine will be the engine oil lubricant for the internal parts of the engine due to the cold as well.

Of course none of these issues are present for a standalone power generator system form boiloff as we are operating it basically in a controlled environment box in the habitat area. Complete with detectors.

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#95 2020-12-29 19:56:23

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut .... here is a quote from kbd512 from over in the Electric topic ...

CO2 exhaust from an ICE can be collected in a zeolite bed and recompressed to feed it back into the engine, which requires more power, but does not represent a major impact on vehicle weight.  In fact, CO2 could be recirculated into the engine to provide the requisite O2 diluent gas / working fluid for combustion to expand, negating the requirement for most of the onboard CO2 storage.

The point about using exhaust CO2 as diluent is ** really ** interesting!

Because the earlier version of this (evolving) concept depended upon blending CO2 with CO at the manufacturing faciltiy, the mass of fuel would have been (roughly) four times greater than the CO would have been alone.

Kbd512's idea of using the exhaust as diluent would mean that only a small supply of diluent would be needed on board to help the engine get started.

So ** now ** our hypothetical future Mars settler would be working with more trades .... some power would be consumed with the recovery process for the exhaust, but ** more ** CO could be carried (about four times more) in the containers for fuel, which means more capacity would be needed for O2.

From my perspective, this topic of yours is becoming ** more ** interesting as we go along.

***
You're certainly right about the need for lubricants, so manufacture of synthetic lubricants is a requirement for the business plan for our hypothetical IC industry on Mars.  I still think that planning to import hydrocarbons from Titan makes a ** lot ** of sense.

***
Here's a map of Delta V to reach various points in the Solar system ... Google came up with it when I asked about Delta V to launch from Titan.

https://www.reddit.com/r/space/comments … ar_system/

I didn't find an answer about Titan, because the map is to ** reach ** points including Titan.

It would be a significant investment to reach Titan with mining and launching equipment, but it should be (relatively)_easy to launch payloads from there. I'm less sure about climbing out of Saturn's gravity well. 

(th)

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#96 2020-12-29 20:34:43

SpaceNut
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From: New Hampshire
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Posts: 23,826

Re: Internal combustion engines for Mars

Hydrocarbons of Titan happens to be just liquid Methane (LCH4) ....something we are making for a mars ship return in great quantities....

LCO is the fuel and LO2 is the oxidizer with the intake from mars the reducing LCO2 as to take the place of Nitrogen....all are in liquid form to keep them concentrated for use with regulators at each tank to allow for the correct outlet pressure for mixing into the engines chamber for ignition. Which seems to fit with a diesel engine due to the heat requirement to phase change the liquid to a gaseous form for use.

On earth the only liquid in a gasoline engine is the gas while the others gaseous in mixing of oxygen with nitrogen so we will need to warm the liquids to force them into phase change before injecting them into the chambers for a mars use.

Using boiloff Hydrogen or methane with oxygen make a gasoline engine very practical with co2 as the diluent for temperature control with its exhaust being reclaimed....

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#97 2020-12-29 20:57:57

tahanson43206
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Re: Internal combustion engines for Mars

For SpaceNut re #96

Can you provide a link to your resource for the type of hydrocarbon at Titan? 

I found this resource showing that there are vast quantities of material NOT methane on Titan:

https://www.nasa.gov/mission_pages/cass … 80213.html

The dark dunes that run along the equator contain a volume of organics several hundred times larger than Earth's coal reserves.

http://knowhow.napaonline.com/how-synth … l-is-made/


Full synthetic, or 100 percent synthetic oils, are usually extracted from crude oil or a byproduct of the same. In the case of Pennzoil, they have figured out how to extract synthetic oil from natural gas.

Titan is likely to be a much more abundant source of hydrocarbons than Mars. 

It appears that synthetic oil can be made from natural gas, of which methane is a significant part.

Mars has Carbon, but water is still unproven, and large quantities of methane from Titan would be an alternative to trying to make methane from locally sourced Carbon and Hydrogen.

(th)

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#98 2020-12-30 10:56:37

SpaceNut
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Re: Internal combustion engines for Mars

https://en.wikipedia.org/wiki/Atmosphere_of_Titan

The atmosphere of Titan is the layer of gases surrounding Titan, the largest moon of Saturn.

It is the only thick atmosphere of a natural satellite in the Solar System.

Titan's lower atmosphere is primarily composed of nitrogen (94.2%), methane (5.65%), and hydrogen (0.099%).

There are trace amounts of other hydrocarbons, such as ethane, diacetylene, methylacetylene, acetylene, propane, PAHs[2] and of other gases, such as cyanoacetylene, hydrogen cyanide, carbon dioxide, carbon monoxide, cyanogen, acetonitrile, argon and helium.

titans-moon-9-728.jpg?cb=1355143225

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#99 2020-12-30 11:19:45

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,981

Re: Internal combustion engines for Mars

For SpaceNut re #98

Thanks for your follow up!   I was hoping you were working from something like that!

The hint I included in Post #97 is that solids on Titan may well be far more complex hydrocarbons than the simple ones floating around in the atmosphere.

I sure hope the probe in discussion for a visit to Titan is designed to look for higher order hydrocarbons, in addition to confirming what observation from probes shows is already there.

(th)

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#100 2020-12-30 19:31:43

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,826

Re: Internal combustion engines for Mars

Found another topic for co use...
Carbon Monoxide - a way to power Mars?

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