Is tomhas dá chuid é slaodacht sreabhán friotaíocht le sreabhadh.
Is airí den sreabhán é a chinneann an méid fórsa a theastaíonn chun é a bhogadh. Dá airde an slaodacht, is gá an fórsa níos mó chun an sreabhach a bhogadh.
Bíonn tionchar ag a theocht ar shlaodacht sreabhán. Dá teo an sreabhach, is lú a shlaodacht. Dá fuaire an sreabhach, is airde a shlaodacht.
Bíonn tionchar freisin ag a bhrú ar shlaodacht sreabhán. Dá airde an brú, is airde slaodacht an tsreabháin.
Is féidir slaodacht sreabháin a thomhas le viscometer. Is gléas é viscometer a thomhaiseann friotaíocht sreabháin chun sreabhadh. Is maoin thábhachtach é slaodacht sreabhán i go leor feidhmeanna. Mar shampla, is féidir slaodacht sreabháin a úsáid chun déan an méid fórsa a theastaíonn chun é a bhogadh trí phíobán a chinneadh.
Tá slaodacht san fhisic ar cheann d’airíonna an ábhair trína dtagann gluaiseacht na móilíní i leith na móilíní mórthimpeall orthu, mar gheall ar fhórsaí idirmhóilíneacha, ar fhórsa frithsheasmhach: i solaid tá sé is airde, ach is ísle i leachtanna agus gáis. Má thumaimid corp eachtrach sa sreabhán atá á bhreithniú, tiocfaidh sé ar fhriotaíocht a bhfuil a neart éagsúil ag brath ar mhéid slaodachta an tsreabháin.
Mar shampla, tá slaodacht níos airde ag molás ná uisce toisc go bhfuil sé níos resistant do shreabhadh.
Tá go leor modhanna ann ar féidir le duine a úsáid chun slaodacht sreabhán a thomhas, agus is é an rud is éasca agus is simplí sféar trastomhas áirithe a scaoileadh isteach i gcoimeádán trédhearcach ina bhfuil an sreabhán a bhfuil a shlaodacht ag iarraidh a chinneadh.
Aird: tugtar fluidity ar chómhalartacht na slaodachta, tomhas réidhe.
Is fachtóir tábhachtach é slaodacht chun na fórsaí a chaithfidh a shárú a chinneadh nuair a úsáidtear leachtanna le haghaidh lubrication agus a iompar i bpíopaí. Beidh sé tábhachtach mar sin dúinn faoistand cén cineál sreabhach an BesaBeidh comhla ® ag obair leis, toisc go mbíonn tionchar ag an bhfrithchuimilt idir ballaí píopa agus an sreabhach a shreabhann tríd ar fheidhmíocht urscaoilte na comhla.
Rialaíonn sé sreabhadh sreabhach isteach processs mar spraeáil, múnlú insteallta agus sciath dromchla.
Slaodacht dhinimiciúil
Déanaimis machnamh ar dhá phlána, scartha le sreabhán (teocht rialaithe) agus comhthreomhar leis each ceann eile, duine amháin ina stad agus an ceann eile faoi réir fórsa a bhrúíonn / a tharraingíonn comhthreomhar leis an eitleán eile.
Ag brath ar an sreabhach a úsáidimid chun an dá eitleán a scaradh, agus i gcónaí ag cur an fórsa céanna i bhfeidhm chun ceann amháin den dá eitleán a bhogadh, feicfimid go n-athraíonn treoluas an eitleáin ag brath ar an sreabhán atá roghnaithe againn.
Ag ginearálú tá:
A (m^2)= achar na bplánaí comhthreomhara
y (m)= fad idir an dá phlána
F (N)= fórsa a chuirtear ar an bplána ag gluaiseacht
u (m/s^2)= treoluas an phlána atá ag gluaiseacht
τ = fórsa tadhlaíoch
Beidh an fórsa tadhlaíoch comhréireach go contrártha leis an fad idir an dá phlána agus comhréireach go díreach leis an luas.
Déanann tabhairt isteach an téarma treoluas rudaí casta, mar go teoiriciúil amháin atá an t-athrú ar an treoluas líneach.
Aonaid tomhais
Sa chóras idirnáisiúnta déantar slaodacht a thomhas i pascals (Pa s) atá comhionann le poiseuille (PI), uaireanta le haghaidh olaí bealaithe úsáidtear an córas CGS freisin, .i. céadchosach (cP)
1 Pa s = 1 PI
1 cP = 1 mPI
Slaodacht Chineamatach: 1 cSt (centiStokes) = 10-6 m2/s
| Leachtacha | Teocht (ºF) | Teocht (ºC) | Slaodacht Chinematach CentiStokes (cSt) | Slaodacht Chinematach Soicind Saybolt Uilíoch (SSU) |
|---|---|---|---|---|
| Aicéatildéad CH3CHO | 61 | 16.1 | 0.305 | 36 |
| Aicéatildéad CH3CHO | 68 | 20 | 0.295 | |
| Aigéad aicéiteach - fínéagar - 10% CH3COOH | 59 | 15 | 1.35 | 31.7 |
| Aigéad aicéiteach - 50% | 59 | 15 | 2.27 | 33 |
| Aigéad aicéiteach - 80% | 59 | 15 | 2.85 | 35 |
| Aigéad aicéiteach - oighreach tiubhaithe | 59 | 15 | 1.34 | 31.7 |
| Ainhidríd aigéid aicéiteach (CH3COO)2O | 59 | 15 | 0.88 | |
| Aicéatón CH3COCH3 | 68 | 20 | 0.41 | |
| Alcól - aillil | 68 | 20 | 1.60 | 31.8 |
| Alcól - aillil | 104 | 40 | 0.90 HP | |
| Alcól - búitile-n | 68 | 20 | 3.64 | 38 |
| Alcól - eitile (gráin) C2H5OH | 68 | 20 | 1.52 | 31.7 |
| Alcól - eitile (gráin) C2H5OH | 100 | 37.8 | 1.2 | 31.5 |
| Alcól - meitil (adhmad) CH3OH | 59 | 15 | 0.74 | |
| Alcól - meitil (adhmad) CH3OH | 32 | 0 | 1.04 | |
| Alcól - próipil | 68 | 20 | 2.8 | 35 |
| Alcól - próipil | 122 | 50 | 1.4 | 31.7 |
| sulfáit alúmanaim - réiteach 36%. | 68 | 20 | 1.41 | 31.7 |
| Amóinia | 0 | -17.8 | 0.30 | |
| Anilín | 68 | 20 | 4.37 | 40 |
| Anilín | 50 | 10 | 6.4 | 46.4 |
| Asfalt RC-0, MC-0, SC-0 | 77 | 25 | 159-324 | 737-1.5M |
| Asfalt RC-0, MC-0, SC-0 | 100 | 37.8 | 60-108 | 280-500 |
| Ola chás chromáin uathoibríoch | 0 | -17.8 | 1295-uas | 6M- uas |
| SAE 10W | ||||
| Ola chás chromáin uathoibríoch | 0 | -17.8 | 1295-2590 | 6M-12M |
| SAE 10W | ||||
| Ola chás chromáin uathoibríoch | 0 | -17.8 | 2590-10350 | 12M-48M |
| SAE 20W | ||||
| Ola chás chromáin uathoibríoch | 210 | 98.9 | 5.7-9.6 | 45-58 |
| SAE 20 | ||||
| Ola chás chromáin uathoibríoch | 210 | 98.9 | 9.6-12.9 | 58-70 |
| SAE 30 | ||||
| Ola chás chromáin uathoibríoch | 210 | 98.9 | 12.9-16.8 | 70-85 |
| SAE 40 | ||||
| Ola chás chromáin uathoibríoch | 210 | 98.9 | 16.8-22.7 | 85-110 |
| SAE 50 | ||||
| Ola fearas feithicleach | 210 | 98.9 | 4.2 min | 40 min |
| SAE 75W | ||||
| Ola fearas feithicleach | 210 | 98.9 | 7.0 min | 49 min |
| SAE 80W | ||||
| Ola fearas feithicleach | 210 | 98.9 | 11.0 min | 63 min |
| SAE 85W | ||||
| Ola fearas feithicleach | 210 | 98.9 | 14-25 | 74-120 |
| SAE 90W | ||||
| Ola fearas feithicleach | 210 | 98.9 | 25-43 | 120-200 |
| SAE 140 | ||||
| Ola fearas feithicleach | 210 | 98.9 | 43 - nóim | 200 min |
| SAE150 | ||||
| Beoir | 68 | 20 | 1.8 | 32 |
| Beinséin (Beinsól) C6H6 | 32 | 0 | 1.0 | 31 |
| Beinséin (Beinsól) C6H6 | 68 | 20 | 0.74 | |
| Ola cnámh | 130 | 54.4 | 47.5 | 220 |
| Ola cnámh | 212 | 100 | 11.6 | 65 |
| Bróimín | 68 | 20 | 0.34 | |
| Bútán-n | -50 | -1.1 | 0.52 | |
| Bútán-n | 30 | 0.35 | ||
| Aigéad búitreach n | 68 | 20 | 1.61 | 31.6 |
| Aigéad búitreach n | 32 | 0 | 2.3 HP | |
| Clóiríd chailciam 5% | 65 | 18.3 | 1156 | |
| Clóiríd chailciam 25% | 60 | 15.6 | 4.0 | 39 |
| Aigéad carbólach (feanól) | 65 | 18.3 | 11.83 | 65 |
| Aigéad carbólach (feanól) | 194 | 90 | 1.26 HP | |
| Teitreaclóiríd charbóin CCl4 | 68 | 20 | 0.612 | |
| Teitreaclóiríd charbóin CCl4 | 100 | 37.8 | 0.53 | |
| Díshuilfíd charbóin CS2 | 32 | 0 | 0.33 | |
| Díshuilfíd charbóin CS2 | 68 | 20 | 0.298 | |
| Ola Castor | 100 | 37.8 | 259-325 | 1200-1500 |
| Ola Castor | 130 | 54.4 | 98-130 | 450-600 |
| Ola adhmaid tSín | 69 | 20.6 | 308.5 | 1425 |
| Ola adhmaid tSín | 100 | 37.8 | 125.5 | 580 |
| Clóraform | 68 | 20 | 0.38 | |
| Clóraform | 140 | 60 | 0.35 | |
| Ola cnó cócó | 100 | 37.8 | 29.8-31.6 | 140-148 |
| Ola cnó cócó | 130 | 54.4 | 14.7-15.7 | 76-80 |
| Ola troisc (ola éisc) | 100 | 37.8 | 32.1 | 150 |
| Ola troisc (ola éisc) | 130 | 54.4 | 19.4 | 95 |
| Ola arbhair | 130 | 54.4 | 28.7 | 135 |
| Ola arbhair | 212 | 100 | 8.6 | 54 |
| Tuaslagán stáirse arbhar | 70 | 21.1 | 32.1 | 150 |
| 22 Báim | 100 | 37.8 | 27.5 | 130 |
| Tuaslagán stáirse arbhar | 70 | 21.1 | 129.8 | 600 |
| 24 Báim | 100 | 37.8 | 95.2 | 440 |
| Tuaslagán stáirse arbhar | 70 | 21.1 | 303 | 1400 |
| 25 Báim | 100 | 37.8 | 173.2 | 800 |
| Ola síolta cadáis | 100 | 37.8 | 37.9 | 176 |
| Ola síolta cadáis | 130 | 54.4 | 20.6 | 100 |
| Amhola 48º API | 60 | 15.6 | 3.8 | 39 |
| Amhola 48º API | 130 | 54.4 | 1.6 | 31.8 |
| Amhola 40º API | 60 | 15.6 | 9.7 | 55.7 |
| Amhola 40º API | 130 | 54.4 | 3.5 | 38 |
| Amhola 35.6º API | 60 | 15.6 | 17.8 | 88.4 |
| Amhola 35.6º API | 130 | 54.4 | 4.9 | 42.3 |
| Amhola 32.6º API | 60 | 15.6 | 23.2 | 110 |
| Amhola 32.6º API | 130 | 54.4 | 7.1 | 46.8 |
| Decane-n | 0 | 17.8 | 2.36 | 34 |
| Decane-n | 100 | 37.8 | 1001 | 31 |
| Gliocól dé-eitile | 70 | 21.1 | 32 | 149.7 |
| Éitear diethyl | 68 | 20 | 0.32 | |
| Breosla díosail 20 | 100 | 37.8 | 44714 | 32.6-45.5 |
| Breosla díosail 20 | 130 | 54.4 | 1.-3.97 | -39 |
| Breosla díosail 30 | 100 | 37.8 | 6-11.75 | 45.5-65 |
| Breosla díosail 30 | 130 | 54.4 | 3.97-6.78 | 39-48 |
| Breosla díosail 40 | 100 | 37.8 | 29.8 max | 140 max |
| Breosla díosail 40 | 130 | 54.4 | 13.1 max | 70 max |
| Breosla díosail 60 | 122 | 50 | 86.6 max | 400 max |
| Breosla díosail 60 | 160 | 71.1 | 35.2 max | 165 max |
| Aicéatáit eitile CH3COOC2H3 | 59 | 15 | 0.4 | |
| Aicéatáit eitile CH3COOC2H3 | 68 | 20 | 0.49 | |
| Bróimíd eitile C2H5Br | 68 | 20 | 0.27 | |
| Bróimíd eitiléine | 68 | 20 | 0.787 | |
| Clóiríd eitiléine | 68 | 20 | 0.668 | |
| Glycol eitiléine | 70 | 21.1 | 17.8 | 88.4 |
| Aigéad formach 10% | 68 | 20 | 1.04 | 31 |
| Aigéad formach 50% | 68 | 20 | 1.2 | 31.5 |
| Aigéad formach 80% | 68 | 20 | 1.4 | 31.7 |
| Aigéad formach tiubhaithe | 68 | 20 | 1.48 | 31.7 |
| Aigéad formach tiubhaithe | 77 | 25 | 1.57 cp | |
| Freon -11 | 70 | 21.1 | 0.21 | |
| Freon -12 | 70 | 21.1 | 0.27 | |
| Freon -21 | 70 | 21.1 | 1.45 | |
| furfurol | 68 | 20 | 1.45 | 31.7 |
| furfurol | 77 | 25 | 1.49 cp | |
| Ola bhreosla 1 | 70 | 21.1 | 2.39-4.28 | 34-40 |
| Ola bhreosla 1 | 100 | 37.8 | -2.69 | 32-35 |
| Ola bhreosla 2 | 70 | 21.1 | 3.0-7.4 | 36-50 |
| Ola bhreosla 2 | 100 | 37.8 | 2.11-4.28 | 33-40 |
| Ola bhreosla 3 | 70 | 21.1 | 2.69-5.84 | 35-45 |
| Ola bhreosla 3 | 100 | 37.8 | 2.06-3.97 | 32.8-39 |
| Ola bhreosla 5A | 70 | 21.1 | 7.4-26.4 | 50-125 |
| Ola bhreosla 5A | 100 | 37.8 | 4.91-13.7 | 42-72 |
| Ola bhreosla 5B | 70 | 21.1 | 26.4- | 125- |
| Ola bhreosla 5B | 100 | 37.8 | 13.6-67.1 | 72-310 |
| Ola bhreosla 6 | 122 | 50 | 97.4-660 | 450-3M |
| Ola bhreosla 6 | 160 | 71.1 | 37.5-172 | 175-780 |
| Olaí gáis | 70 | 21.1 | 13.9 | 73 |
| Olaí gáis | 100 | 37.8 | 7.4 | 50 |
| Gásailín a | 60 | 15.6 | 0.88 | |
| Gásailín a | 100 | 37.8 | 0.71 | |
| Gásailín b | 60 | 15.6 | 0.64 | |
| Gásailín b | 100 | 37.8 | ||
| Gásailín c | 60 | 15.6 | 0.46 | |
| Gásailín c | 100 | 37.8 | 0.40 | |
| Glicerin 100% | 68.6 | 20.3 | 648 | 2950 |
| Glicerin 100% | 100 | 37.8 | 176 | 813 |
| Glicerin 50% uisce | 68 | 20 | 5.29 | 43 |
| Glicerin 50% uisce | 140 | 60 | 1.85 HP | |
| Glúcós | 100 | 37.8 | 7.7M-22M | 35M-100M |
| Glúcós | 150 | 65.6 | 880-2420 | 4M-11M |
| heipitín-n | 0 | -17.8 | 0.928 | |
| heipitín-n | 100 | 37.8 | 0.511 | |
| Heacsán-n | 0 | -17.8 | 0.683 | |
| Heacsán-n | 100 | 37.8 | 0.401 | |
| mil | 100 | 37.8 | 73.6 | 349 |
| Dúigh, printéirí | 100 | 37.8 | 550-2200 | 2500-10M |
| Dúigh, printéirí | 130 | 54.4 | 238-660 | 1100-3M |
| Ola inslithe | 70 | 21.1 | 24.1 max | 115 max |
| Ola inslithe | 100 | 37.8 | 11.75 max | 65 max |
| ceirisín | 68 | 20 | 2.71 | 35 |
| Breosla Scaird | -30. | -34.4 | 7.9 | 52 |
| Lard | 100 | 37.8 | 62.1 | 287 |
| Lard | 130 | 54.4 | 34.3 | 160 |
| Ola bhlonaige | 100 | 37.8 | 41-47.5 | 190-220 |
| Ola bhlonaige | 130 | 54.4 | 23.4-27.1 | 112-128 |
| Ola rois | 100 | 37.8 | 30.5 | 143 |
| Ola rois | 130 | 54.4 | 18.94 | 93 |
| Mearcair | 70 | 21.1 | 0.118 | |
| Mearcair | 100 | 37.8 | 0.11 | |
| Aicéatáit meitile | 68 | 20 | 0.44 | |
| Aicéatáit meitile | 104 | 40 | 0.32 HP | |
| Iaidíd Methyl | 68 | 20 | 0.213 | |
| Iaidíd Methyl | 104 | 40 | 0.42 HP | |
| Ola Menhaden | 100 | 37.8 | 29.8 | 140 |
| Ola Menhaden | 130 | 54.4 | 18.2 | 90 |
| Bainne | 68 | 20 | 1.13 | 31.5 |
| Molás A, ar dtús | 100 | 37.8 | 281-5070 | 1300-23500 |
| Molás A, ar dtús | 130 | 54.4 | 151-1760 | 700-8160 |
| B, dara | 100 | 37.8 | 1410-13.2M | 6535-61180 |
| B, dara | 130 | 54.4 | 660-3.3M | 3058-15294 |
| C, strap dubh | 100 | 37.8 | 2630-55M | 12190-255M |
| C, strap dubh | 130 | 54.4 | 1320-16.5M | 6120-76.5M |
| Naftailéin | 176 | 80 | 0.9 | |
| Naftailéin | 212 | 100 | 0.78 HP | |
| Ola Neatstool | 100 | 37.8 | 49.7 | 230 |
| Ola Neatstool | 130 | 54.4 | 27.5 | 130 |
| Nitrobenzene | 68 | 20 | 1.67 | 31.8 |
| Neamháin-n | 0 | -17.8 | 1728 | 32 |
| Neamháin-n | 100 | 37.8 | 0.807 | |
| Ochtan-n | 0 | -17.8 | 1266 | 31.7 |
| Ochtan-n | 100 | 37.8 | 0.645 | |
| Ola olóige | 100 | 37.8 | 43.2 | 200 |
| Ola olóige | 130 | 54.4 | 24.1 | |
| Ola pailme | 100 | 37.8 | 47.8 | |
| Ola pailme | 130 | 54.4 | 26.4 | |
| peanut ola | 100 | 37.8 | 42 | 200 |
| peanut ola | 130 | 54.4 | 23.4 | |
| Peinteán-n | 0 | 17.8 | 0.508 | |
| Peinteán-n | 80 | 26.7 | 0.342 | |
| Peitriliam | 130 | 54.4 | 20.5 | 100 |
| Peitriliam | 160 | 71.1 | 15 | 77 |
| Éitear peitriliam | 60 | 15.6 | 31(st) | 1.1 |
| Aigéad propionic | 32 | 0 | 1.52 HP | 31.5 |
| Aigéad propionic | 68 | 20 | 1.13 | |
| Próipiléin glycol | 70 | 21.1 | 52 | 241 |
| Múchadh ola | 100-120 | 20.5-25 | ||
| Ola ráibe | 100 | 37.8 | 54.1 | 250 |
| Ola ráibe | 130 | 54.4 | 31 | 145 |
| Ola roisín | 100 | 37.8 | 324.7 | 1500 |
| Ola roisín | 130 | 54.4 | 129.9 | 600 |
| roisín (coill) | 100 | 37.8 | 216-11M | 1M-50M |
| roisín (coill) | 200 | 93.3 | 108-4400 | 500-20M |
| Ola síolta sesame | 100 | 37.8 | 39.6 | 184 |
| Ola síolta sesame | 130 | 54.4 | 23 | 110 |
| Clóiríd sóidiam 5% | 68 | 20 | 1097 | 31.1 |
| Clóiríd sóidiam 25% | 60 | 15.6 | 2.4 | 34 |
| Hiodrocsaíd sóidiam (sóid loiscneach) 20% | 65 | 18.3 | 4.0 | 39.4 |
| Hiodrocsaíd sóidiam (sóid loiscneach) 30% | 65 | 18.3 | 10.0 | 58.1 |
| Hiodrocsaíd sóidiam (sóid loiscneach) 40% | 65 | 18.3 | ||
| Ola pónaire soighe | 100 | 37.8 | 35.4 | 165 |
| Ola pónaire soighe | 130 | 5.4 | 19.64 | 96 |
| Ola sperm | 100 | 37.5 | 21-23 | 110 |
| Ola sperm | 130 | 54.4 | 15.2 | 78 |
| Aigéad sulfarach 100% | 68 | 20 | 14.56 | 76 |
| Aigéad sulfarach 100% | 140 | 60 | 7.2 HP | |
| Aigéad sulfarach 95% | 68 | 20 | 14.5 | 75 |
| Aigéad sulfarach 60% | 68 | 20 | 4.4 | 41 |
| Aigéad sulfarach 20% | 3M-8M | |||
| Aigéad sulfarach 20% | 650-1400 | |||
| Tar, oigheann cóic | 70 | 21.1 | 600-1760 | 15M-300M |
| Tar, oigheann cóic | 100 | 37.8 | 141-308 | 2M-20M |
| Tar, teach gáis | 70 | 21.1 | 3300-66M | 2500 |
| Tar, teach gáis | 100 | 37.8 | 440-4400 | 500 |
| Tar, péine | 100 | 37.8 | 559 | 200-300 |
| Tar, péine | 132 | 55.6 | 108.2 | 55-60 |
| Tolúéin | 68 | 20 | 0.68 | 185.7 |
| Tolúéin | 140 | 60 | 0.38 HP | |
| Glicól triethylene | 70 | 21.1 | 40 | 400-440 |
| Glicól triethylene | 185-205 | |||
| Tuirpintín | 100 | 37.8 | 86.5-95.2 | 1425 |
| Tuirpintín | 130 | 54.4 | 39.9-44.3 | 650 |
| Vearnais, spar | 68 | 20 | 313 | |
| Vearnais, spar | 100 | 37.8 | 143 | |
| Uisce, driogtha | 68 | 20 | 10038 | 31 |
| Uisce, úr | 60 | 15.6 | 1.13 | 31.5 |
| Uisce, úr | 130 | 54.4 | 0.55 | |
| Uisce, farraige | 1.15 | 31.5 | ||
| Ola míol mór | 100 | 37.8 | 35-39.6 | 163-184 |
| Ola míol mór | 130 | 54.4 | 19.9-23.4 | 97-112 |
| Xiléin-ó | 68 | 20 | 0.93 | |
| Xiléin-ó | 104 | 40 | 0.623 HP |
