3.3.26 · D1Electric pump-fed cycle — modern innovation
Ek rocket engine ko liquid fuel ko ek aisi chamber mein jabardasti dalna hota hai jo pehle se crushing pressure par hai, aur isse saste mein karne ka ek hi tarika hai — pump. Yeh page — bilkul zero se — har symbol, ratio, aur picture build karta hai jo aapko electric pump-fed cycle samajhne se pehle chahiye, taaki jab aap P = m ˙ Δ p / ρ
Yeh toolbox page hai. Parent note (Rocket Propulsion → Electric pump-fed cycle ) in symbols ko use karta hai; yahan hum inhe ek-ek karke kamate hain.
p us area par spread hokar jis par woh push karti hai . Agar ek force F A p = A F pascal (Pa) hai, jo ek newton ko ek square metre par spread karna hai.
Apna angutha flat table par dabao: halka lagta hai. Ab usi push se drawing pin dabao, chhoti si tip: dard hota hai. Same force , tiny area → bahut bada pressure . Pressure matlab force concentrated hona.
Rocket wale log "pascal" kam bolte hain. Woh bar bolte hain:
Topic ko yeh kyun chahiye: poori problem yahi hai ki "chamber pressure p c andar dalna mushkil hai." Pressure woh villain hai jisse hum lad rahe hain.
Yeh is topic ke liye pressure ki sabse important re-reading hai.
Definition Pressure = har cubic metre mein packed energyUnits dekho. Pressure hai metre 2 newton m 2 N = m 3 N ⋅ m = m 3 joule ek joule (energy) hota hai. Toh pressure bhi hai — fluid ke har cubic metre mein stored joules of energy .
Intuition Yeh kyun matter karta haiFluid ka pressure Δ p Δ p dalne padte hain. Woh ek sentence pump-power formula ka seed hai. Ise pakde rakho.
Symbol Δ "change in" hai — koi quantity kitni badhi ya ghati. Toh Δ p
ρ ρ mass per volume — cheez kitni tightly packed hai:
ρ = V m [ m 3 kg ] ρ = 1000 kg/m 3
Do identical boxes: ek pankh se bhara, ek lohe se. Same volume, bilkul alag mass. Density wohi batata hai jo dono mein fark karta hai. Rocket kerosene (RP-1) paani ke kareeb hoti hai, lagbhag 1000 kg/m 3
Topic ko yeh kyun chahiye: pumps is hisab se rate hote hain ki woh kitna liquid volume move karte hain, lekin rockets mein hisab mass mein hota hai (kyunki thrust mass phenkne se aata hai). Density woh bridge hai jo dono ko convert karta hai. Iske bina aapka power formula galat units mein aayega — parent note exactly yahi galti flag karta hai.
Rocket koi static bucket nahi hai; propellant iske andar se stream karta hai. Toh humein rates chahiye.
Definition Volume flow rateV ˙ V ˙ liquid ka volume jo har second ek point se guzarta hai , m 3 / s
Definition Mass flow ratem ˙ m ˙ har second guzarne wala mass , kg/s
Yeh density se jude hain, kyunki mass = density × volume:
Topic ko yeh kyun chahiye: power energy per second hai, isliye sab kuch per-second quantity hona chahiye. Dot notation hi "per second" ko saath lekar chalta hai.
P aap energy kitni tezi se deliver karte ho :
P = time energy [ watt = joule/second ]
Intuition Pump power apne dimaag mein assemble karo
Har cubic metre ko Δ p
Aap V ˙
Toh energy per second = Δ p × V ˙
V ˙ = m ˙ / ρ P ideal = ρ m ˙ Δ p
Us boxed formula ka har letter ab kuch aisa hai jo aapne banaya hai, na ki memorise kiya.
η η useful output ÷ input , hamesha 0 aur 1 ke beech ki sankhya. Agar pump η p = 0.6
divide kyun karte ho
Kyunki η < 1 η bada banata hai. 0.6 se divide karna 1.67 se multiply karna hai. Subscripts sirf batate hain kaunsa stage: η p η m
Topic ko yeh kyun chahiye: ideal formulas optimistic hote hain; do efficiencies "physics-perfect" power ko "battery se real electrical draw" mein convert karti hain.
Definition Battery specific energye b Battery ke har kilogram mein stored joules , J/kg e b Battery specific energy .
Intuition Poora trade-off ek line meinkilograms of battery = kitna hard P × kitna lamba t b ÷ battery kitni achi e b kyun yeh cycle chhote, short-burn stages ke liye suit karta hai.
Definition Specific impulseI s p propellant ki har unit se kitna thrust nikala — rocket ki fuel economy. Yeh lagbhag poori tarah combustion chamber se set hoti hai, na ki fuel wahaan kaise pahuncha isse. Dekho Specific impulse (Isp) .
Common mistake "Fancy pumpI s p Kyun sahi lagta hai: modern = har taraf se behtar.
Fix: pump sirf decide karta hai ki propellant kaise deliver kiya jaye; jalna I s p simplicity aur cost mein jeette hain, aur dead battery weight uthate hain. "Delivery method" aur "combustion quality" ko alag mental boxes mein rakho.
Pressure as energy per volume
Flow bridge m-dot = rho V-dot
Ideal pump power P = m-dot dp over rho
Power = energy per second
Efficiency eta pump and motor
Burn time t and specific energy e
Har arrow ek dependency hai: battery mass tab tak nahi samjha ja sakta jab tak power na samjho, aur power tab tak nahi samjha ja sakta jab tak pressure-as-energy aur flow bridge na samjho.
Taaki parent ke comparisons samajh aayein, teen feed families abhi naam lo:
Pressure-fed cycle — koi pump nahi, tanks hi high pressure hain (bhaare tanks).Turbopump-fed cycle (gas generator vs staged combustion) — hot gas se spin hoti turbine pump chalati hai.Electric pump-fed — battery + motor pump ghuma ta hai (topic khud; jaise Rocket Lab Rutherford engine ).
Teeno ko aakhir mein Tsiolkovsky rocket equation se judge kiya jaata hai, kyunki har extra kilogram — battery ho ya tank steel — aapka mass ratio kha jaata hai. Aur "pump ke through pressure smoothly kyun badhti hai" ki reasoning Bernoulli's principle par lean karti hai.
Daayein side chhupao; kya aap har cheez memory se bata sakte ho?
p = F / A Force, jis area par push karti hai uspar spread hoti hai; unit pascal.
Pressure ko joules per cubic metre kyun padha ja sakta hai? Kyunki N/m² = N·m/m³ = J/m³, isliye pressure har unit volume mein stored energy hai.
Symbol Δ "Change in" — koi quantity kitni badhi ya ghati, jaise Δ p
ρ Density, mass per volume, kg/m³ (paani ≈ 1000).
Kisi letter ke upar dot ka kya matlab hai? "Per second" — ek rate, jaise m ˙
m ˙ V ˙ m ˙ = ρ V ˙ V ˙ = m ˙ / ρ
Power aur uska unit define karo. Har second deliver ki gayi energy; watt = joule per second.
P ideal Har m³ ko Δ p V ˙ = m ˙ / ρ P = m ˙ Δ p / ρ
η Efficiency (0–1); real power = ideal ÷ η, jo bada hota hai, losses cover karne ke liye.
e b Battery specific energy, har kilogram mein stored joules, J/kg.
Battery-mass logic words mein batao. kg = power × burn time ÷ specific energy (energy needed ÷ energy per kg).
Kya pump choice I s p Nahi — chamber mein combustion I s p
