>
✔ 100% Money-Back Guarantee on Eligible Items
✔ Prices Displayed in Your Local Currency
✔ Final Price = No Surprise Import Fees
✔ Complimentary Insured Worldwide Shipping on Qualifying Orders
✔ Select Collector & Specialty Pieces May Require Secured Delivery Handling
by Nikolai Kulev (Author)
This study deals with the investigation regarding the behavior of liquid cryogenic propellants in the launcher upper stages under microgravity with superheated tank walls. It contributes in this way to the application-oriented basic research by describing mathematically and quantifying experimentally the influence of evaporation on the interface reorientation of cryogenic liquids. In broader terms this work shows, both in a mathematical and an experimental way, the influence of the heat and mass transfer in the fluid and solid phases on the linear momentum transfer in the liquid phase due to the coupling of the transfer mechanisms. The main assumption behind this study is based on the principle that the solution of a partial differential equation depends on its boundary condition. In this case these are the mass balance boundary conditions at the interface and the contact line. These boundary conditions relate the respective liquid and the interface velocities to the mass flux due to interfacial evaporation, or phase change in general. A mathematical description of the reorientation was developed implementing an equation for the contact line boundary condition which takes explicitly into account the evaporation or the wall superheat at the contact line, respectively. Both the contact line velocity and the contact line angle become functions of the evaporation at the contact line and accordingly of the related dimensionless numbers. The implementation of the contact line boundary condition completes the equation system describing the non-isothermal flow macroscopically. A joint scaling approach of all field equations and boundary conditions was developed through which the influence of evaporation on the capillary-driven motion was expressed mathematically. This influence on the motion of the whole interface was experimentally quantified, too. For that purpose cryogenic liquids were used in drop tower experiments at ZARM, University of Bremen, with varying wall temper
- In stock, ready to ship
- ✔ Authenticity Guaranteed — Verified Designer Goods
- ✔ Sourced from Authorized European/U.S. Luxury Distributors
- ✔ Secure Checkout — SSL Encrypted Payments
- ✔ Fast Global Delivery — 3–11 Business Days
- ✔ Easy Returns on Eligible Items
- ✔ 100% Money-Back Guarantee — Full Refund if Not Satisfied
AUTHENTICITY GUARANTEED
Reserved for you — complete your purchase to secure this piece.
OFFICIALLY AUTHORIZED RESELLER
Discover Officially Authorized Authentic Items at STORE7994.com - Certificates Available on Request!
Independently verified for store quality and customer safety.
Trust score: 91/100
All designer items offered by STORE 7994 are sourced from trusted luxury distributors and verified through independent authentication services.
Learn how STORE 7994 authenticates luxury items
Guaranteed Authentic — Includes Brand Documentation & Third-Party Verification Options.
Shipping information
- Free Shipping* on all orders over $300 USD to most countries* Estimated delivery: 2-5 business days Mon-Sat to U.S., CA, EU etc.
- Tracking available: DHL Express
- Store 7994 Shipping policy
- Global delivery in 3–9 business days (location dependent).
- Free Worldwide Shipping $300+. International duties & VAT are calculated by destination country and may be collected upon delivery. UK orders are subject to 20% import VAT upon delivery.
Our innovation isn’t just in the brands we carry — it’s in the way we connect them. From our automation engine that keeps collections globally updated to our commitment to authenticity-first presentation, STORE 7994 exists where timeless design meets modern precision.
Every product we offer is:
Elevated · Intentional · Exclusive · Authentic
STORE 7994 is an authorized reseller of luxury fashion houses. Certificates and proof of authenticity are available to brand owners and partners upon request.
Returns & Refunds
We want you to shop with confidence at STORE 7994. If your purchase does not meet expectations, eligible items may be returned under the conditions below.
Return Eligibility
Items must be unused, unworn, and in original condition with all tags, packaging, and accessories included. Items showing any signs of wear or damage will not be accepted.
Return Window
Return requests must be made within 14 days of delivery.
Return Shipping
Customers are responsible for return shipping costs unless the item is defective, damaged, or incorrect.
Luxury Items
Items valued over $1,000 may be subject to a 7% restocking fee upon approved return.
Non-Returnable Items
For hygiene and product integrity reasons, the following items are final sale once opened or used:
• Underwear
• Fragrances
• Any worn or used items
Made-to-Order Items
Custom-designed products, including STORE 7994 hoodies, are made exclusively for each customer and are final sale. These items are not eligible for return or exchange unless defective or incorrect.
If you receive a defective or incorrect item, please contact us and we will make it right.
International Shipping & Duties
Many of our products ship directly from trusted international partners. Any applicable customs duties or import taxes are calculated at checkout and are non-refundable, even if the item is returned.
Returns & Associated Fees
All approved returns are subject to a $24 return processing fee. For international orders, duties, taxes, and return fees will be deducted from the original payment.
Shipping Policy
Complimentary shipping is offered on orders over $300. Orders below this threshold are subject to standard shipping rates at checkout.
