Hydrodynamics and in-water propulsion of amphibious land vehicles

About Us


Like a crocodile is adapted
for both land and water life
through evolution;
all amphibious vehicles are
optimized according to
specifications for both
land and water missions.

offers a turn-key
hydrodynamic solution package:
Form hydrodynamic design of the vehicle
till complete product validation.

Maximizing performance by optimizing requirements

Milpod team is determined to provide our customers with innovative and tailor-made systems that ensure optimal operation in water.

By utilizing and integrating our technologies, experience and competencies within design, analysis, product development and testing we aim to give our customers a complete solution:

One-stop service for all amphibious propulsion requirements

Defining Vehicle Requirements

CFD Analysis

Preliminary Propulsion System Design

Optimization of Propulsion System with FEM & CFD

Combined Vehicle+Propulsion Analysis

Detailed Mechanical Design

Critical Design Review

Configuration Management

Prototype Production

Product Tests

Training (Operator/Maintenance Level)

Vehicle Tests

Integrated Logistic Support


Prototype & Serial Production

The MILPOD design team has been working on the design and production of propulsion systems for many years.
This experience allows MILPOD to produce superior products in terms of performance, material and production quality.
Working in close contact with the vehicle designer/manufacturer, we tailor the production process according to the quality system and reporting requirements.


At MILPOD, we undertake the overall responsibility of amphibious land vehicles’ in-water performance; including both the vehicle’s geometric optimization and development of best possible propulsion system.

Propulsion system design, analysis and optimization

At MILPOD we design optimal propulsion systems for amphibious land vehicles, such as water jet, podded-propeller or ducted propeller according to the resistance analysis, wake characteristics, end-user requirements and specified rules or regulations. This approach contains a design spiral which gets inputs from hydrodynamic design and mechanical design; resulting in the prototype production for land tests. MILPOD can offer custom solutions as well as existing off-the-shelf product groups.

Wake and Propulsion Reduction Analysis

Open-water hydrodynamic characteristics of the propulsion system are adjusted according to the wake fraction and thrust deduction of the vehicle body. The wake fraction is responsible for a horizontal shift. The thrust deduction takes account for the increase in the vehicle body resistance due to the propulsion system operation. For this approach, a detailed calculation and a realistic simulation of hull resistance at different speeds are required. We use advanced wake flow tools for predicting the flow characteristics behind the vehicle body and use these data at the early stages of the propulsion system design.

Hydrostatics and Stability Analysis

Characteristic parameters calculated for the floating vehicle, which can either directly be used to comment on the nature of stability of the vehicle or be used to evaluate other stability parameters.

Resistance and Power Analysis

In order to calculate the required propulsion power of an amphibious land vehicle, the resistance and the total propulsive efficiency need to be determined with the highest accuracy possible. At MILPOD this is done by using advanced and customised Computational Fluid Dynamics (CFD) methods. The primary objective is to predict power and resistance curve for different vehicle speeds. Two-phase domain set up, free surface capturing methods, imposed or solved motion (up to six degrees of freedom) calculations and wave generation methods for various sea and weather states are used not only for the highest accuracy but also in order to provide physical reality.

Vehicle Geometry Optimization

Resistance analysis results show possible drag recovery areas on the vehicle geometry such as high-pressure accumulation fields, swirl areas and appendages that cause undesirable additional resistance. By using advanced CAD and optimisation tools, problematic areas are re-designed to decrease resistance on the vehicle body. All these optimisation study results enable customers to get cost-effective propulsion system solutions with reduced power requirement for the same target speed.

Turning circle

This is the most common maneuver for vehicle operation. It has a whole lot of hydrodynamic interaction involved and needs to be calculated by using unsteady motion analysis. Free surface capturing, degrees of freedom of body and realistic motion simulation needs very small calculation time steps, huge flow/motion domain and fine meshes. It is one of the most time-consuming analysis type. We use RANS and Particle Based CFD solutions to solve these cases.

Dynamic Stability Analysis

Dynamic stability analysis gives the stability information of a vessel considering dynamic behavior of different sea conditions. These sea conditions have many different parameters such as wavelength, wave height, wave periods and wind speed. However, all these parameters can affect vehicle from any direction. We solve these unsteady problems using six degrees of freedom and free surface capturing technics in time domain and predict critical positions of the vehicle which have to be avoided.

Self-righting Analysis

For amphibious land vehicles, analysis of self-righting ability (from upside down to upright position) is essential for the determination of recovery time and time dependent position. We solve these problems using rigid body motion and Particle Based CFD technics.

Crash Stop Analysis

The requirement of the crash stop analysis comes not only from navigation emergencies, such as collision and grounding, but also tactical operational maneuvering needs of amphibious land vehicles. The first objective is to change the direction of propulsion forces to astern while the vehicle is moving ahead and calculate stopping time by using time depended on analysis. But moreover, forces must be checked on propulsion system (especially propeller or rotor for waterjet) for this extraordinary condition. We use Finite Element Method (FEM) to check propeller/rotor structural condition and other parts of the propulsion system interface to the vehicle body.

Sea-Shore Transaction Analysis (Landing, Beaching)

For amphibious land vehicles, sea-shore transaction analysis is especially critical. This type of analysis gives information about water–vehicle body interaction while entering to water and propulsion system sufficiency while getting out of water at any coastal ramp profile and vehicle speed. We solve these problems using rigid body motion and Particle Based CFD technics.


MILPOD has a dedicated team of experienced engineers on hydrodynamics and propulsion of amphibious land vehicles.


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